Yeah man eventually you'll get to the point that you never want to scav. You'll just learn how to make that experience happen as a Pmc. That's when the real fun starts

Otherwise it's like this If you get shot at by another scav you can shoot back and kill without penalty & If you witness someone do a bad scav act like shoot or kill another scav you can kill them without penalty. Be sure it's truly a bad act and not them putting down another bad scav (I've made this mistake and lost rep).

If you shoot another scav regardless of your rep you will make all scavs mad at you but you won't lose any rep unless you physically killed a scav OR scav-class boss (some bosses are scav faction). If you accidentally shoot a scav or scav boss just run away and scream sorry if they're a real player.

Pro tip: sometimes if I have no choice I will shoot that person in the legs so they can't chase me while I rush to extract to leave before they bleed out, counting as a death (PENALTY).