I'll Just start with the class idea so far then explain my idea after.

The Storm Trooper

Alignment: Any
Hit Die: d10
Class Skills:
The Storm Trooper's Class skills (and the key ability for each skill) are: Climb (Str), Craft (Int), Heal (Wis), Intimidate (Cha), Jump (Str), Listen (Wis), Search (Int), Sense Motive (Wis), Spot (Wis), Swim (Str), and Tumble (Dex).
Skill Points at 1st Level (4 + Int modifier) ×4.
Skill Points at each additional level 4 + Int modifier

Table: The Storm Trooper
{table=head] Level | BAB | Fort | Ref | Will | Special
1 | 1 | 2 | 2 | 2 | Form Fitting, Bonus Feat
2 | 2 | 3 | 3 | 3 | Armour Focus, Combat Focus
3 | 3 | 3 | 3 | 3 | Uncanny Dodge, Improved Shield Bash
4 | 4 | 4 | 4 | 4 | Infallible Resolve, Bonus Feat
5 | 5 | 4 | 4 | 4 | Armour Specialization
6 | 6\1 | 5 | 5 | 5 | Evasion, Sword and Board Fighting
7 | 7\2 | 5 | 5 | 5 | Rapid Movement, Bonus Feat
8 | 8\3 | 6 | 6 | 6 | Combat Leap, Keen Senses
9 | 9\4 | 6 | 6 | 6 |Greater Armour Focus
10 | 10\5 | 7 | 7 | 7 | Greater Armour Specialization
11 | 11\6\1 | 7 | 7 | 7 | Improved Uncanny Dodge
12 | 12\7\2 | 8 | 8 | 8 | Slippery Mind, Bonus Feat
13 | 13\8\3 | 8 | 8 | 8 | Improved Evasion, Mettle
14 | 14\9\4 | 9 | 9 | 9 | Greater Rapid Movement
15 | 15\10\5 | 9 |9 | 9 | Cushioned fall
16 | 16\11\6\1 | 10 | 10 | 10 | Aerial Superiority, Bonus Feat
17 | 17\12\7\2 | 10 | 10 | 10 | Supreme Armour Focus
18 | 18\13\8\3 | 11 | 11 | 11 | Supreme Armour Specialization
19 | 19\14\9\4 | 11 | 11 | 11 | Arcane Resistance
20 | 20\15\10\5 | 12 | 12 | 12 | Fortification, Bonus Feat
[/table]

Now (in spoilers as it's quite long) the class features descriptions:

Class Features
All of the following are class features of the storm trooper.
Spoiler
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Weapon and Armor Proficiency
A Storm Trooper is proficient with all simple and martial weapons and with all armor (heavy, medium, and light) and shields (including tower shields).

Form Fitting
Basic training accustoms the storm trooper to the weight of armour. He suffers no movement speed penalty from heavy armour, or large shields.

Bonus Feat
At first level, and at every fourth level after (4th. 8Th, etc) the storm trooper gains a bonus feat. This can me any martial, general, skill or save feat. The Storm Trooper must still meat the prerequisites for the feat however.

Armour Focus
The Storm Trooper gains Armour Focus as a bonus feat.

Combat Focus
Starting at 2nd level the storm trooper can use his storm trooper level to count as fighter levels for taking fighter specific feats (Ie: Weapon Specialization). Also, any Armour Focus/Specialization feats the storm trooper has for shields count at Weapon Focus/Specialization for that shield in granting additional damage and to hit bonuses.

Uncanny Dodge (Ex)
Starting at 3rd level, a storm trooper can react to danger before his senses would normally allow him to do so. He retains his Dexterity bonus to AC (if any) even if he is caught flat-footed or struck by an invisible attacker. However, he still loses his Dexterity bonus to AC if immobilized.

Improved Shield Bash
At 3rd level the storm trooper gets the benefit of the Improved Shield Bash Feat.

Infallible Resolve (Ex)
Starting at the 4th level, a storm trooper no longer automatically fails a saving throw on a roll of 1. He can still fail the save if he doesn't meet the DC however.

Amour Specialization
The Storm Trooper gains Armour Specialization as a bonus feat.

Evasion (Ex)
At 6th level and higher, a storm trooper can avoid even magical and unusual attacks with great agility. If he makes a successful Reflex saving throw against an attack that normally deals half damage on a successful save, he instead takes no damage. Evasion can be used only if the storm trooper is wearing armor that he has Armour Specialization in, or no armor. A helpless storm trooper does not gain the benefit of evasion.

Sword and Board Fighting
Starting at 6th level the storm trooper can make shield bashes with their shield and attack with their weapon at the same time. Unlike two weapon fighting there is no attack penalty and they add their full strength modifier (instead of half as normal for off hand attacks). In addition the storm trooper can make as many irradiative attacks with their 'off hand' as their 'main hand'.

Rapid Movement (Ex)
Quick movement speed is as important as heavy armour in avoiding danger. Starting at 7th level and higher the storm trooper gains +10ft movement speed as long as he is wearing armour he has Armour Specialization in, or is un-armoured.

Combat Leap (Ex)
Starting at 8th level the storm trooper can do a combat leap as a full round action. The target in question must be at least 30ft away. The storm trooper must then make a running jump check to cover the distance, however they gain a bonus to that check equal to their current movement speed. If they make the check they land in front of the target and get to make an attack at their highest BaB. They also gain a bonus to hit equal to half their level, and a damage bonus equal to quarter that (or half if using a two handed weapon). There is no limit to the number of times an encounter/day this can be used.

Keen Senses (Ex)
Starting at 8th level the storm trooper adds half their storm trooper level to any spot, search, listen, and sense motive check. In addition if they pass a hidden or invisible object they gain a passive observation check as if they had actively 'taken 10' on a spot, listen and/or search check.

Greater Armour Focus
The Storm Trooper gains Greater Armour Focus as a bonus feat.

Amour Specialization
The Storm Trooper gains Greater Armour Specialization as a bonus feat.

Improved Uncanny Dodge (Ex)
A storm trooper of 11th level or higher can no longer be flanked.
This defense denies others the ability to sneak attack the character by flanking him, unless the attacker has at least four more 'rogue' levels than the target does.
If a character already has uncanny dodge from a second class, the character automatically gains improved uncanny dodge instead, and the levels from the classes that grant uncanny dodge stack to determine the minimum 'rogue' level required to flank the character.

Slippery Mind (Ex)
Starting at 12th level storm troopers gets to roll two d20 instead of one to make a saving throw against a mind effecting attack/spell, and take the highest of the two rolls.

Improved Evasion (Ex)
At 13th level the storm trooper's Evasion is more powerful. He still takes no damage on a successful Reflex saving throw against attacks henceforth he takes only half damage on a failed save. A helpless storm trooper does not gain the benefit of improved evasion.

Mettle (Ex)
At 13th level the storm trooper can resist magical attacks more than most others. If you succeed a saving throw against a Fortitude or Will that would normally produce an effect on a successful save (Will half or Fortitude partial) you instead ignore that effect. Mettle does not benefit an unconscious or sleeping storm trooper.

Greater Rapid Movement (Ex)
The Storm Trooper is even faster in his armour. The storm trooper gains an additional +10ft movement speed as long as he is wearing armour he has Armour Specialization in, or is un-armoured.

Cushioned fall (Ex)
At 15th level the storm trooper can negate some falling damage. If he makes a Reflex save equal to (10 + 1 per 10 feet up to DC 30 @ 200ft) he only takes halve damage. This only works if he is wearing armour he has Armour Focus in. In addition Evasion does not apply to this as you usually cannot save for half falling damage.


Aerial Superiority (Ex)
Starting at the 16th level the storm trooper may attempt to down flying opponents with a Combat Leap. They would preform the leap check as normal, but instead of attacking they make a grapple check with a bonus equal to half their class level. If they succeed they then throw their opponents downward tearing them out of the sky inflicting damage equal to 1d6 per 5 feet fallen (up to 20d6 damage maximum). However, if the opponent is strong enough to lift the storm trooper over their head they can make an opposing strength check to throw the storm trooper off them, interrupting the attack.


Supreme Armour Focus (Ex)
This feat functions much like (Greater) Armour Focus. The storm trooper gains an additional +2 to AC with any armour he has (Greater) Armour Focus with. This bonus applies to -multiple- feats (IE all armour focus) instead of one like Greater Armour Focus.

Supreme Armour Specialization (Ex)
This feat functions much like (Greater) Armour Specialization. The storm trooper reduces the armour check penalty by -2, and max Dex bonus by 2 with any armour he has (Greater) Armour Specialization with. This bonus applies to -multiple- feats (IE all Armour Specializations) instead of one like Greater Armour Specialization, and allows a positive armour check (IE Bonus) if the penalty is reduced past 0.

Arcane Resistance (Ex)
At the 19th level the storm trooper is so resilient he emits a slight anti-magical aura around him. Any spell targeting him (or something on him) that allows a save must make a spell penetration check equal to 10+The storm trooper's relevant saving throw.

Fortification (Ex)
At the 20th level the storm trooper gains a 50% chance to negate any critical hit as long as he is wearing armour he has Armour Focus in. This -stacks- with the Fortification armour enchantment, multiple pieces of armour with armour focus and similar spells (IE if his armour already has 50% Fortification, this increases that to 100% effectively making him immune to critical hits).


Also, Armour Spec/Focus [based of something the Giant had on here a while ago but I think I reversed them or something] :
Spoiler
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Armour Focus [Combat]
Pre-req
Proficiency in the chosen armour/shield
Benefit
You gain +1 AC with the chosen armour/shield
Special
You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new category of armour/shields.

Armour Specialization [Combat]
Pre-req
Proficiency in the chosen armour/shield, Armour Focus with chosen armour/shield
Benefit
Your armour check penalty decreases by 2, and your max Dex increases by 2 with the chosen Armour/Shield. You cannot gain a negative armour penalty with this.
Special
You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new category of armour/shields.

Greater Armour Focus [Combat]
Pre-req
Proficiency in the chosen armour/shield, Armour Focus with chosen armour/sheild
Benefit
You gain an additional +2 AC with the chosen armour/shield. This stacks with Armour Focus.
Special
You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new category of armour/shields.

Greater Armour Specialization [Combat]
Pre-req
Proficiency in the chosen armour/shield, Armour Specialization with chosen armour/shield
Benefit
Your armour check penalty decreases by an additional 3, and your max Dex increases by 3 more with the chosen Armour/Shield. You cannot gain a negative armour penalty with this.
Special
You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new category of armour/shields


Now essentially I was aiming for a mid-tier (~3, maybe high 4) martial class with good survivability. Something that replaces your average guard, or works as a shock trooper in the army (hence the improved movement, perception, and reduced penalty in armour). However they should still be capable of damaging stuff, so full BAB, bonus feats and some offensive features I added in.

What I would like the know the most:
1) Does the class make sense and have synergy well with it's self? I tried to make the class features supportive or base off each other.
2) Is it too niche? Does it step too much on published base classes (and I mean the viable ones, IDC if it makes the Core Fighter, obsolete for example).
3) If it's too weak? If so any ideas for more/revamped features.
4) Does anything not make sense? Like you THINK the skill means something but might have some bad RAW implications?