There are a set of conventions used by most broadsheets called the Ximenean conventions (after one of the classic setters) and this doesn't quite meet them, but it is heading in the direction.. It fails because some of the clues have more than half of their squares "unchecked" by other clues. Also 2, 2 letter words.
It's all round solid, with many of the clues coming from a failed attempt with some students to write a poem of cryptic couplets which rhymed and whose answers made another cryptic clue. That's why 8 Ac and 9 Ac are so similar and why 12 Dn has two parts. The others from the poem didn't make the cut.