The name has an accent.
As for the clash word, see my post regarding the title. At first sight, there are several possibilities for some clashes.
15d Anagram with extra letter
21d Definition is the last word. Wordplay is 1+3+1+1
27d Key word is 'principally'. Apply it to some of the words.
Some contributors seem to have found this not too hard. Personally, I found it a bit of a pain. I suppose it just depends what wavelength you're on.