Done, I think. Not quite sure of the relevance of the name. Very challenging and enjoyable. Some very clever cluing. Thanks, Leo!
Smelly, you're on the right track. 2+1+2+1. That was my last. The meaning of the definition still eludes me.
Crowded, I read 'all other' to mean that clues either clashed or were missing letters. Some of the missing letter clues are fiendish.
I did scratch my head for a while wondering if twelve clashes necessarily meant twelve pairs of entries clashing, but I couldn't see any other arrangement.