So many of these categories I want to ask more questions about before I score myself.

My current DM, no surprise, gets bingo easily and almost blacks out the whole board.

So I assume the logic behind rewarding players for RP / backstory effort being a bad thing is because the other players assume that rewarding someone else = punishing them? I have often had players complain about this, not because I give them any mechanical rewards, but because the players who care about the world and their character's place in it tend to have a lot more spotlight time and adventure hooks centered around their character or their background. Its kind of a self sustaining cycle.

Also, is having enemies fight to the death that unusual? I check morale for my enemies (when I remember to), but in my experience most DMs have most monsters fight to the death all the time, I don't think its unusual at all.