Hmmm, not aware of the new rules but will ask DS. Yes, detentions are given but mostly fairly I think - DS forgot some basic equipment twice in past week. First time warned, second time 30 min detention. I have no problem with that. I work in a school and I know from calls I take from parents that DCs are sometimes less than forthcoming with real reasons for detentions!!
Most schools have a "keep your hands and feet to yourself" rule.
We had a funeral to attend last year and I felt it was poorly handled by the school in the sense we got the blanket unauthorised letter for a day's absence (it was in the north of England) with no mention of condolences etc (not essential, but a nice touch) and a pretty unempathetic (if that's a word) call from the attendance officer. I spoke to HOY, and they were pretty mortified about it, and very sympathetic to the situation, partic as DS had 100% attendance. For any absence you generally have to make up time after school. When I went to HOY, the time DS had to catch up with was cancelled. For parents who perhaps don't engage and support the school to get the best results for their DCs, I can imagine there might be a different response.
No school wants kids to be absent, particularly now the new curriculum is so much more dense and requires every moment of teaching time, but again, we've never had any issues when DS has been ill, although this hasn't been very often.
I think it's important to have a good relationship with the school and pick battles when you really need too - which I can say has been once in the time DS has been there, and that was re funeral absence.
It has a new head now and he looks promising. No school is perfect but, as mentioned previously, DS is very happy and I am too.
You have to think about your child though. It wouldn't have been the right school for DD, although she would have been perfectly fine there, but she's very different from DS and didn't need the same, more rigid, structure around learning.