I know what you mean. I bought vol.1 and 2 as my first ever things to buy that got me into it and while hooked, it didn't have make me go OUCH sometimes. It's a very Joker-style mania and I think that's deliberate.
I've been wondering about that. The first time Tim appears to be using a more Jason like tone, he gets bitch slapped a lot as well so you could be right about it being editorial. I think for Jason, this was a great move and one that was forgotten about. They could have played it off with escalation but it feels like they took a cheap way out (extra-traumatised psycho boy) instead of a meaningful (long term effects of killing on him and the city). That's my theory, anyway.