D&D's weapon statistics have been kept simple for a reason: simplicity. Sure, you can add lots of little modifiers of this kind, but you're quickly going to realize that this kind of small modifiers is a) not going to have much of a felt impact in-game, and b) going to necessitate a lot of extra bookkeeping. For example, you'll have to keep weapon modifiers close to hand whenever your PCs are fighting humanoid opponents.
Some games do this kind of thing, and do it successfully - BUT it always results in lots of table-referencing, on-the-fly-calculating, jotting-down-of-quick-notes etc. For example, Hârnmaster (for a long time my system of choice in the past), a d% based system, has the following weapon statistics for each and every weapon in the game:
1. Impact ratings (basically, this is weapon base damage), separated into blunt, piercing, and slashing impact ratings (the widely used broadsword has 3 blunt, 5 slashing, 4 piercing; the poleaxe just has 6 blunt, 9 slashing). You can use whatever damage type you like, so long as your weapon provides it, without penalty - according to what armor the opponent wears, and what you want to do, different damage types will be more or less useful.
2. Attack/Defense modifiers. Some weapons are better for an attack, some are better for parrying, some strike a nice balance. Compare modifiers to opponent's weapon's modifiers (attack compares vs. defense and vice versa): for every point your value is better, you get a +5% bonus on your roll. Broadswords have A/D 3/2, poleaxes have A/D 5/1. Note that some weapons have overall better statistics compared to others (e.g. a dagger is a good weapon damage-wise, it's light and affordable, but its A/D sucks: 2/1; a quarterstaff has great A/D: 4/3, but unimpressive damage).
3. Cost in pence, with most metal weapons and stuff like longbows shockingly expensive.
4. Weight in pounds. Since overall weight carried affects every single physical activity you undertake, this matters. I'll spare you the horrid calculation of overall encumbrance and its mechanical impact.
5. Weapon quality (WQ), usually a number somewhere between 8 (bad) and 13 (good), although better-made weapons can be had for a price. If you use your weapon to parry, if you fumble it, if your opponent targets your weapon etc., a quality roll can be called for. Roll 3d6; if the total exceeds your weapon's quality, reduce quality by the difference permanently (can be fixed, though). If the total exceeds your weapon's quality by more than half, your weapon breaks. Tough luck. This actually happens quite a bit.
6. Handedness. Using a big weapon in just one hand can impose penalties (like the aforementioned poleaxe: -20%). Using a weapon in your off hand can impose more or less severe penalties, depending on the weapon (broadsword: -10%). Using a big weapon in your off-hand alone is really tough (poleaxe: -30%). Using a broadsword in one or two hands makes no difference. Since shields are really, really good in Hârnmaster, using two-handed weapons (which often have great impact and attack ratings, but poor defense ratings) is a risk not undertaken lightly.
7. Ranged weapons have range, of course, separated into range categories. It's often very easy to hit stuff close up (you get a small bonus on your attack), but very hard to hit anything at extreme range (large penalties).
8. You can get heavier-than-normal melee weapons made on demand, which increase impact if you're really strong, but actually decrease impact and chance of hitting if you're a weakling (refer to table xyz...).
9. Some weapons are noted as to be chivalric weapons, meaning only members of the nobility are expected to wield such a weapon. Swords and lances usually fall in this category. A peasant with a sword will often have to answer unpleasant questions about where he got it. Some other weapons are peasant weapons and unfit for knights to use (flails, polearms, crossbows etc.).
10. Some weapons have special rules associated with them, of course. For example, a poleaxe can be equipped with a spike, which adds the option of attacking with a piercing impact of 6, but reduces weapon quality, increases weight and price... you see where this is going.
Oh, for comparison, the Hârn statistics of a spear: impact B4, P7; A/D 4/2; handedness -10/-20; WQ 10?... forgot the rest. But yeah, spears are really, really good weapons in Hârnmaster. The only reason swords still fare well in comparison is their ease of use in one hand, their versatility where impact types are concerned, and their good quality. But they also cost a fortune, which a spear doesn't. I've always loved the spear in Hârnmaster and was pretty sad that D&D doesn't acknowledge what a good weapon it is.