i'm not saying it's overpowered. i'm saying it's good, because you don't need a dedicated healer.
there's going to be regular medkit respawn time, but no internal self-cooldown. that would be stupid and unintuitive.
Balance medkits to the point of stupidity, misuse of medkits could be very bad.
Also, add hurtboxes, that touching does damage. Think a killbox, but it hurts you. Its a much better add in then the acid you mentioned earlier, because it means you can make your own acid by combining hurtboxes and water. Plus, it would allow for me to make my fallout themed megaton map involving radiation.