RE: Who gives a s236?
I think that the policy reasoning behind s236 remains (to be at least) opaque. Neighbourhood budgets already exist in many authorities. Although s236 is about functions and not budgets, the two need to go hand in hand. I imagine that many authorities have either:
1) looked at s236 and consider that their existing ward budgets system (if it exist) is adequate;
2) looked at s236 and are unwilling to devolve too much discretion over service delivery to individual wards for fear that it will result in ward-level "postcode lotteries".
3) not looked at s236 at all - ie, they are completely unaware of it.
Whichever it is, I don't expect that you will find a slew of authorities who have made use of it. I could be wrong though.