No, we don't see any evidence of this at all in the ethnographic literature. To the contrary, what we tend to see is antisocial actors being socially ostracized or killed by the larger group. This is evidently a very old behavior since we absolutely see it in chimp bands as well which means that it goes all the way back to our most recent common ancestor which existed 6 million years ago.

Generally, no. Hierarchy is not the natural order, it's an ideological virus that has been shoved down our throats.

No human is so strong they can face a group, and everyone can be killed with a knife while they sleep. The group can kick someone out or even kill them, but the leader can't just go around like a dictator (if they even had a leader, generally power was not in the hands of just one person). A tribe is like an extended family, you'd have a lifelong personal relationship with everyone - you'd have to be a real asshole to even have to worry about that

Bad stuff happened obviously, but generally people lived like animals - they had territory and would fight other groups over it, but people didn't live in fear and chaos

It takes agriculture and specialization to do the truly terrible stuff. If you don't have people dedicated to being soldiers or guards, you can't wage war (bloodfeuds just aren't in the same ballpark) or impose your will by force. If you don't have agriculture, you don't have much stuff, so it's probably not worth raiding you.

And yeah, people might be stolen or enslaved, but generally there's a path to integration - again, no dedicated guards, so how long can they really keep you in line through force before it gets old?

Not if they wanted loyal tribesmen companions. And not if they wanted to avoid being killed in their sleep.