We have a keyboard full of unused keys, Please separate the loot and interact commands.
This really effects engineers more than other classes because between wave of attacking enemies we want to go and loot all the bodies with out accidently picking up our turrets.
Same goes for picking up the warriors banner.
Other times during escort missions you might want to quickly loot the area but instead you stop and speak with the npc.
None of which are game breaking, just really annoying.