Back to weapons... I'd also like to see a more commonly used AK (AK-47 anyone?
).
Also the more M16 variants, the better, as IMO each has its advantages and disadvantages. M16A4 (which imo should replace M16A2) and M4A1 are relatively more accurate yet heavier, and allow attachments on the flattop rail. M4A1 being slightly less accurate at long ranges yet lighter and easier to manuver with. Car-15 is almost same as M4A1 in looks, but doesn't have the recoil compensating flash hider and is less accurate, but it's significantly lighter and can still use a scope over the carrying handle and attachments that go to the handguards, including trijicon agoc reflex sights, flashlights, m203 etc. Then we have the commando - like M4A1 (or like car-15, not sure, I think both types exist), only less accurate and even easier to move around with. m203 is problematic on this one. Of course, it may be difficult to model all, but the models are relatively similar to eachother so I may be wrong. Anyway, none of them will be a "useless" one.
As for M16 attachments, if in the future you won't have to re-model the weapon for every attachment combination, I think the M16 series weapons should have at least trijicon acog reflex, trijicon agoc 4x, harris bipod, m203, flashlight and LAM. Also possible to add aimpoint, and if NV is added, an aquilla 4x (which I can give technical details for if needed).
UZI: I wouldn't ever use the original one, as it's 3.5kg empty and uses 9mm... If u want an Uzi I would take one of the shorter ones (mini or micro) so that at least you enjoy its very short length considering u suffer from weak 9mm ammo.
M82 is an effective and commonly used long range sniper rifle (yes, against people too and not only against materials). Definately more used in millitaries than the robar, isn't it?
Pistols - I believe having at least 1 glock variant (if not more) would be nice, though I never really use pistols. If they are made significantly easier to aim fast with them though (which is a completely another issue) then it may be worth the investment adding glocks.
MGs: Although FN MAGs are still used in armies (yes, man-portable too), I don't see people taking it in-game, as for the ranges in INF the minimi is many times more effective, as well as MGs being overall ineffective in the INF environment. It, of course, would be cool to have, if one would have the time to invest in it. Just don't forget that it's basically impossible to aim it (and very hard to aim the minimi btw) in standing and crouch, though in prone both should be very deadly weapons.
Also weapons with tripods (M2HB and possibly FN MAG) should be easier to actually use in-game, starting by making it possible to actually aim them.