It's very hard to say "take ofsted with a pinch of salt" though. Schools are partially judged on the data, and if children are not making expected progress or achieving, the school will get a lower ofsted grade. This can lead to the school entering a downward spiral with a falling roll and less money, and even worse outcomes. At some point, the school may be graded inadequate and then be taken over by a MAT or given a new head and things will change anyway.
There are schools, maybe very rural ones, for example, where parents can't realistically chose to send their children elsewhere, that will suffer less from this. There are also schools where all the children come from the sort of home/background that means they will be supported and so most will achieve anyway, regardless of what the school does. Most schools do not fall into this category, and so have to care about ofsted/results.
It can be very hard for individual teachers to speak up, and they cannot change the system. Ultimately, it is their job, and they have to balance keeping their income with how much they are willing to speak out/go off piste.
I agree that a lot is asked of children in Year 2- probably far too much. Some schools are better than others at managing this.
However, I would speak to the teacher re: daydreaming etc- ultimately, she cannot just let him opt out of participating in whatever the class are doing. I agree that it would be good to find strategies to help him- but those can't be "only let him do things he finds interesting" or "let him ignore instructions". The second can be a safety risk too.
It may be worth looking at other schools too, to see if you like any of them better. I do agree most English schools don't do play based learning in Year 2, but some may offer more music/PE/drama/art etc which may suit him better, or may generally feel less "hot house".