Ok, so it's probably that I just take more hit in the head anyway ;p.
Another thing about the suggestion: I think it can really decrease PK. I mean, many people are just afraid when you enter in their encounter. If instead of killing, they'd just neutralise you, maybe they will talk to you and, who know, heal you.
And it will add big interest to medic, while I think it's very slow to heal someone in fight if you have not FA (or change for second hand, or long click...), so add a shortcut to use stims fast could be good.
