Hello i have alot of suggestions based on my experience and experience of other players that are actively grinding and ranking up their XP.
First suggestion is that there should be "assisted" xp, for example 2 people are shooting the zombie, and who shoots the final bullet get awarded max xp, but the assisted one should atleast get half the XP in my opinion, because u shoot shoot and someone steals it from u, its kinda dumb not gonna lie.
Second suggestion is that there should be more pistols to upgrade, dual berretas, fiveseven, etc, no one buys guns except the glock and the balrog, it should be more variant to other guns beside them.
Third suggestion is that /guns should be removed or nerfed for example u have 15 seconds of the game to type /guns after that is impossible to use /guns, because alot of people abuse the /guns feature when zombie "Deimos" gets their gun and they get a brand new gun, or they abuse it to get a new he grenade.
Fourth suggestion, nerf the smoker by alot, this thing that can go through walls is cool, but its too long, almost 30-40 seconds hold is impossible to escape from.
Fifth suggestion, make the charger ability only usable when on ground not when u jump so u get so much boost, charger in l4d2 can only go on land not air, and make his ability do more damage when u hit people directly.
Sixth suggestion, make the chainsaw zombie getting hurt sound different than a boomer, alot of people play in cl_minmodels 1 which disables the models of zombies and only by sound its possible to recognize what zombie it is.
Seven suggestion, the witch ability cooldown is too long compared to chargers and other zombies, plus it got nerfed by her speed in the new update u could rework that.
Eight suggestion, the deagle that shoots fireworks sometimes when u directly hit zombies or even splash near them, damage doesnt register , its kinda annoying when running away from 2 or 3 zombies.
Ninth suggestion, make the zombies have some sort of spawn protection when they dont move for like 1-2 seconds, because instantly getting killed without being able to move is absurd.
Tenth suggestion, make the melee weapons do knockback, for example the baseball bat knocks zombies away.
Eleventh suggestion, add an upgrade for the smoke grenade, its kinda useless now it doesnt do anything, maybe it could be a tear gas that does 500-1000 dmg a second idk.
Deimos ability should be able to disarm the player without a directy hit because it splashes his ability on impact, doesnt need to be direct.