Stuck on 33ac:
Running leet, sited where it runs and was running.
The only possible answer I can see begins with B - but unless there's a misprint in the clue I can't see why.
I was in the same boat too. Also puzzled by 20d. As far as I can see there's only one possible answer, having all the crossers, but can't locate the meaning as per the clue in Chambers. Otherwise all done and happy with.