I'm stuck on the top right corner and one in the bottom left. Hints only please.
3A Saucy PM? Less fat (8) - I don't have any letters for this but I think it might be an anagram of ATERNOON (afternoon with "f" missing).
4D Poets (6) ??K?R? - The first letter of this is the second letter of 3A.
5D Music hall (5) ??E?N - I think this might be ODEON, which makes "O" the fourth letter of 3A.
6D Mad setter is esteemed (5) ??A?E - I think "setter" might be "ME" which makes this ??AME.
7D Rooms in closes (4) ??D? - I think this might be ENDS, but I can't tally that with "Rooms".
And finally ...
25D Fine fellow (4) ?C?T - The obvious answer is SCOT (unless you play football of course), but ECHT parses quite well.