Help my inexperienced DM. What could go wrong?

[OldTrees]

My inexperienced DM is making a few new house rules. Our group also contains a powergamer who tries and fails to make slightly superior character to the average.

Our group is melee heavy:
Swordsage
Minotaur Barbarian
Elven Werebear Warshaper
Paladin of Slaughter/Orc Warlord
Rogue
(Eldritch Glaive build) Warlock/Knight
Sorcerer (metamagiced Fireball blaster)
CoDZilla

My DM has made the following changes

Animal Companion
Druids use the 3.0 Animal Companion rules with max HD per animal = 1/2 Druid level
Rangers still uses 3.5 Animal Companion rules but the Natural Bond feat is eliminated

BAB:
Each character has a Good, Average and Poor score equal to their levels in classes with Good, Average and Poor BAB.

A character has a Good iterative attacks if their Good score equals or exceeds their Average and Poor Scores.
A character has a Average iterative attacks if their Good score equals or exceeds their Poor Scores.
Else Poor iterative attacks

iterative attacks:
Good: extra attack every -3
Average: -4
Poor: -5 (normal)

Examples

Fighter 20
Cleric 20 (Divine Power at levels 7-20)
Wizard 20
Wizard 5/Fighter 1/Eldritch Knight 10/Wizard 4
Wizard 1/Cleric 3/Mystic Theruge 10/Cleric 6
{table=head]Level|Fighter|Cleric|Wizard|Eldritch Knight|Mystic Theruge

1st|
+1|
+0|
+0|
+0|
+0

2nd|
+2|
+1|
+1|
+1|
+0

3rd|
+3|
+2|
+1|
+1|
+1

4th|
+4/+1|
+3|
+2|
+2|
+2

5th|
+5/+2|
+3|
+2|
+2|
+2

6th|
+6/+3|
+4|
+3|
+3|
+3

7th|
+7/+4/+1|
+7/+3|
+3|
+4|
+3

8th|
+8/+5/+2|
+8/+4|
+4|
+5|
+4

9th|
+9/+6/+3|
+9/+5/+1|
+4|
+6/+1|
+4

10th|
+10/+7/+4/+1|
+10/+6/+2|
+5|
+7/+4/+1|
+5

11th|
+11/+8/+5/+2|
+11/+7/+3|
+5|
+8/+5/+2|
+5

12th|
+12/+9/+6/+3|
+12/+8/+4|
+6/+1|
+9/+6/+3|
+6/+1

13th|
+13/+10/+7/+4/+1|
+13/+9/+5/+1|
+6/+1|
+10/+7/+4/+1|
+6/+1

14th|
+14/+11/+8/+5/+2|
+14/+10/+6/+2|
+7/+2|
+11/+8/+5/+2|
+7/+2

15th|
+15/+12/+9/+6/+3|
+15/+11/+7/+3|
+7/+2|
+12/+9/+6/+3|
+8/+3

16th|
+16/+13/+10/+7/+4/+1|
+16/+12/+8/+4|
+8/+3|
+13/+10/+7/+4/+1|
+8/+3

17th|
+17/+14/+11/+8/+5/+2|
+17/+13/+9/+5/+1|
+8/+3|
+14/+11/+8/+5/+2|
+9/+4

18th|
+18/+15/+12/+9/+6/+3|
+18/+14/+10/+6/+2|
+9/+4|
+14/+11/+8/+5/+2|
+10/+5

19th|
+19/+16/+13/+10/+7/+4/+1|
+19/+15/+11/+7/+3|
+9/+4|
+15/+12/+9/+6/+3|
+11/+6/+1

20th|
+20/+17/+14/+11/+8/+5/+2|
+20/+16/+12/+8/+4|
+10/+5|
+15/+12/+9/+6/+3|
+11/+6/+1
[/table]

Two Weapon Fighting:
Two Weapon Fighting penalties have been eliminated instead the off hand fights at a worse iterative attack penalty. Normally the penalty is 3 grades worse than your primary hand.

Two Weapon Fighting
Prerequisites: Dex 15
Benefit: Your off hand's iterative penalty lessens by 1.

Improved Two Weapon Fighting
Prerequisites: Dex 17, 6HD
Benefit: Your off hand's iterative penalty lessens by 1 more.

Greater Two Weapon Fighting
Prerequisites: Dex 19, 12HD
Benefit: Your off hand's iterative penalty lessens by 1 more.

Off Hand Attacks
{table=head]|Fighter20|Rogue20|Wizard20

Normal|
+20/+14/+8/+2|
+15/+8/+1|
+10/+2

Two Weapon Fighting|
+20/+15/+10/+5|
+15/+9/+3|
+10/+3

Improved Two Weapon Fighting|
+20/+16/+12/+8/+4|
+15/+10/+5|
+10/+4

Greater Two Weapon Fighting|
+20/+17/+14/+11/+8/+5/+2|
+15/+11/+7/+3|
+10/+5

[/table]

[NecroticPunch]

My god.... A fighter with greather two weapon fighting could be attacking 14 times... with no magical items.... my god.

[jiriku]

Well, I doubt those changes will break your game. They just seem...needlessly complicated.

Except for the druid animal companion thing. Druids do NOT need the help, and they do NOT need more units and more stat blocks to keep track of.

The increased number of iterative attacks is going mean that as your level increases:

1) melee characters deal more damage than expected. Monsters that function primarily by entering melee combat will be less challenging, because they won't have the hit points to survive there for long.
2) PCs will be less mobile than expected. The better your full attack is, the more you're punished in combat for doing anything other than a full attack. Moving around starts to carry a high opportunity cost, so whenever possible, PCs won't move.
3) The swordsage is going to suck. Because most of his maneuvers can't be combined with a full attack, he won't be invited to the damage party that everyone else is celebrating at.


Edit: My biggest concern would be that there don't seem to be obvious reasons for any of these changes. It's like your DM is doing it just to do it. D&D is a complicated game, and there's a lot to keep track of. House rules make it more complicated, which is an especially big problem for a new DM. Each and every house rule should justify its existence by contributing something valuable to the game. Different for different's sake doesn't cut it.