I think that the debris is a great idea. And definite AI suppression. Though the player should not be forced to take cover by other effects, or have some sort of blur thing going on because then that means you can't take the risky strategy if you need to because you can't see.
Plus, although I think the AI suppression would be good, I don't really understand the point of it. Since AI don't run away unless there's 1 left there's no point, might as well just shoot them as quickly as possible so they can't shoot back and you're not wasting rounds shooting near them.
Saying that, it still would be interesting for the sake of advancement tactics. Because if you shoot at AI when others are trying to move up they just continue to shoot regardless of all the bullets hitting very close to them when you're trying to suppress so your guys can move up.