1] No Commando
2] No Juggernaut
3] No OMA
4] No akimbo or duel wielding bullshit (ex: akimbo P90's or Model 1887s, even though those were fun as ****.)
5] Possibly no stopping power [If everyone would have the same bullet damage (And the damage better not take like 4 shots just to kills someone, more like 2.) it would make the game fair.]
6] No ABSOLUTELY NOT sniper rifle hitmarkers (If you were to get shot by a sniper rifle it would blow your ****in head off, no way what so ever could someone survive a .40 caliber bullet or more.) And can you believe that someone without stopping power, and a silenced sniper rifle couldn't kill someone by shooting them in the head? That's just ****ed up.
7] No hitmarkers if you were to shoot anyone in the head (This should include every gun, EVERY.) It's just completely retarded to have someone survive a gunshot to the head in MW2.
8] No deathstreaks (Or at least not pain killer.)
9] No Cold-Blooded (I know many people use it and its good but its simply to unrealistic if you're out in the open 10 ft. away from attack helicopter and it won't shoot you.)
10] No getting killed from killstreaks when you're concealed (And I mean from this: If you're laying down in a gillie suit, in tall grass, crouching, in the back of the map a harrier is not going to magically see you and kill you.)
11] Increase explosive damage (I know it may be cheap but if you have a grenade and you're 10 ft. away and you survive, again its ****ed up.)
12] No killcams (If you're doing good and you kill someone, the person you kill will see you're killcam, see where you are, hunt you ****in down, and slit your god damn throat. Again fake beyond fake.)
13] Scavenger's abilities should be limited (If you randomly go to a dead guy's body and find a scavenger pack. You're not automatically for sure going to find a noob tube in it. Or a javelin round. Or a stinger round. Or an AT4-HS round. The scavenger pack can't even fit one of those big ass explosive rounds in that little ****in waist pouch.) It should have grenades and shit in the pouch at random.
14] Make bullets fall downwards after long distances or some wind resistance.
15] Make victims bodies react to physical damages. (Ex: If you shoot someone in the head have a ton of blood and show the head blow off. Same with arms and legs and various parts of the body. If you shoot them show some more blood and gore. The games not meant for some little ****in 10 year old so stop ****ing catering to those little assholes! World at War a predecessor of MW2 even had some physical damages shown, like being blown up from a artillery strike.)
16] If you shoot with an unsilenced weapon, you won't immediately no where to ****in pin point where the person's position is. (If the person shoots multiple times, or maybe just a 1/3 chance if you shoot you will be seen on radar. And all of this goes if you are actually in range with the person shooting. You're not going to pin point someones position from 10 miles away.
There's a hella of a lot more. Leave in the comments below some and I'll add them in to this post.