Some suggestions i have, feel free to troll.
About cover system:
-why only objects like tables and sandbags make covers? i think windows and cars should be too. as the cover system is a "work in progress" feature it shouldn't be aplied only to furnitures.
-you shouldn't be able to shoot (with a gun that use bullets, NOT explosives) a person laying down right behind a cover or a window, exept when very close to him.
-give deployable weapons a bonus to accuracy when deployed next to a cover, that will make sense i think.
-some covers should be destroyable.
-give hability to create temporary sandbags with the use of empty bags and a shover/pickaxe thats u use to fill them with ground concreate or sand, or just buyable?
About doors:
-breach charges should make a little damage and wind or disorient in a small radius.
-add a "door breacher" or give super sledge a "use" ability to destroy doors (with chances of failure depending on str and doors types)?
About stuff:
-long range weapons/snipers should have an accuracy malus when firing in close range.
-running speed depending on total weight (already suggested) and agility?
-make ability/perk to throw back grenades when walking on them?
-utility items who give certains bonuses but lock the slot for other purpuses:
ex: grenade bandolière (minus ap to throw nades), pouched jacket (minus ap to reload), scavenger bag (more carrying capacity), night vision google, gaz mask ( already proposed), etc...
- ability to booby trap corpses with a mine to prevent resurection?
-add the ability to "carry" knocked/dead people?
-destroy armor when player get criticaly killed (goo, flame, etc...).
-legendary armors(not sure about that)?
-ability to craft multiples items at once (this is important).
about other stuff:
-arenas where players could do things like quick deathmatchs, tdm, ctf with randoms weapons (that would atract many players who don't want to grind the core and just want to see the gameplay mechanics).
sorry for the grammar bad spelling and so, my english teacher commited suicide by cancer when i was young.