15 across: Sweet sole trader? (7)
Excellent double-definition clue, one that had me thinking of fish at first: sweet = COBBLER = sole trader.
5 down: Poet raised with poor taste — does he leave this raised then? (6, 4)
Very amusing: poet raised with poor taste = ELIOT raised with TSEAT = TOILET SEAT = does he leave this raised then?
28 across: It descreases livestock fly with livestock? (5)
A nice one that took a while to click: livestock fly with livestock = BOT OX = BOTOX = it decreases (de-creases).