I think a distinction we need to make here is that we're talking about a realistic system here, not a historically accurate system. The way I see it, a realistic fantasy system is a way to apply the laws of the real, physical world (physics) to a fictional world. Therefore the physics of weaponry is relevant - what actual historical weaponry was like, less so.

This post will be devoted mainly to the topic of weapons, with tangential points on damage, wounds and armor:

Damage Types:

Although there are variable and variables to spare, you can break the damaging attacks of an edged weapon down into three pretty broad categories: Chop, Slash and Thrust. You can also bash with an edged weapon, but you aren't really using it as an edged weapon at that point. Arguably every weapon should have the option to Bash, with the effectiveness based on the characteristics of that weapon.

(Descriptions are, of course, somewhat simplified)
A chop is when the edge connects more-or-less straight, with the force going inwards towards the target - the blade is driven into the target. Chopping attacks are tighter than slashes and create deeper, if smaller, wounds.
A slash is when the blade is primarily moving across the target, and the cutting action is caused by the blade slicing the target as it travels across. Slashing attacks create the largest possible wound sizes, but they are often shallower and require large movements to execute.
A thrust is when the weapon is inserted into the target point first, using its point to part the target and allow the blade entry for a significant length. Thrusts are good at penetrating armor and have a greater chance of an instantly fatal wound, but produce less bleeding than chops or slashes.
A bash is any blunt force attack made with the weapon; with a sword this would usually be using the pommel as the contact point, but it could be elsewhere. Bashes bypass most armor and cause concussion damage instead of bleeding.

Each of these broad damage forms corresponds roughly to a type of attack and weapon handling. In general, I think the wielder of the weapon should have the choice of which attack form to use, with the different damage types causing different wounding effects. Most weapons are best at only one or two damage types - the Katana (my own personal weapon of choice) would come out strong on the slash, weaker on everything else. Other weapons wouldn't be able to do some damage types at all. In game system terms, this helps to give weapons more meaningful differences other than just a single pure damage statistic: when fighting an unarmored opponent you might use a slashing attack for maximum damage, but if your opponent has chain mail on you'll have to switch to thrusting (or precision slashing, but I'll cover that later) which your weapon might be much worse at.

Just like weapons have strengths and weaknesses in various damage types, so does armor; chain armor is excellent against slashing attacks, only decent against thrusts and not very good at all against crushing. Most armor doesn't provide equal coverage to the entire body - a mail hauberk may leave the lower arms and legs exposed, and a cuirass leaves the limbs with weaker protections than the torso. There should be some ability to choose not only your attack type but the general target of your attack, with corresponding adjustments to the difficulty of the attack and its results.

Important Weapon Attributes:

In addition to the type and degree of damage they are capable of dealing, there are a few other attributes that are very important to weapons:

Speed: This represents the attack speed of the weapon, how fast it maneuvers, can be moved from offense to defense; it would have an effect on the difficulty of blocking the weapon and perhaps on whatever version of attacks per round exists in the system. If recovery is not a separate attribute, speed would account for recovery.
Reach: An underrated but very important aspect, reach is exactly what is sounds like: the striking distance of the weapon. Note that this is not the same thing as the length of the weapon - it is the distance from which an effective attack may be delivered. The reach of a primary thrusting weapon is always going to be better than a slashing weapon, and the reach of a shield bash is effectively zero.
Recovery: I'm not sure if recovery should be part of speed or not. Recovery is how long the weapon takes to ready for another attack after executing one. A 12lb sledgehammer would have excellent damage, but terrible recovery. Weapons with poor recovery time usually involve large movements to use, are very heavy, or both.
Fatigue: This is how much using the weapon in combat physically drains the wielder. The above mentioned 12lb sledge will very quickly tire its user out, whereas a knife will do so not significantly faster than fighting unarmed.
Blocking Ability: How many ways the weapon has to block an attack, if its strong enough to block an attack, if it can be used to snare an attack, etc. I'm not really sure how to implement this one as a numerical attribute.

An example weapon statistic block might look something like this (the values here are largely arbitrary, since there isn't any system to go with them - I favor a 100 based system, so they're based on that):

Katana
2 pounds, 28" blade, 38" overall
Chop 60
Slash 95
Thrust 60
Bash 30
Speed Good [this would be a number in a real system]
Reach Moderate [this would be a number in a real system]
Recovery Moderate [this would be a number in a real system]
Fatigue Light [this would be a number in a real system]

--=-=--

That's it for this post. I think the ability to make decisions such as area and type of attack ought to not only make combat more realistic, but give back some of the 'options' some people feel are lacking from melee fighters - these are the sort of options a real fighter chooses among, not whether or not to activate their Iron Tiger Heart Blinding Surge or whatever.

Next time I mean to discourse a bit about my thoughts on a basic combat system. I think a realistic system pretty much needs to focus on physical combat and treat magic as an extension of physics, so physical combat is going to be very important. One of the big mistakes D&D makes is treating magic as though it operates on utterly different rules than the rest of the world, rather than just being another way to manipulate those rules - which is more of how I see it. If magic works within the laws of physics (through some dark matter or however else you want to explain it) it helps to keep it scaling at a reasonable pace with physical warriors, and flat-out eliminates some of the more troubling aspects. I'll elaborate on this concept later as well.