I have no idea how to parse my answer for 4 ac, or 41 ac. Help would be appreciated with 46ac and 12 d, please. So far I have just 4 clashes, despite completing 80+ % of the grid!
4A - Perth implies Scottish for first word
41A - Have you spotted who set the crossword?
46A - straightforward reversal (I would know 'mate' as I'm a cockney)
12D - first 4 letters again slang for 'problems' with last letter missing