Hello - I've been struggling with this on and off all afternoon and like you, peterm, had identified 25A as a type 2, defined by 21A, but I can't parse it. I can't work out what this profession word is, or no different from (like, same?).
Also having trouble with 27A. I have the answer - it's a type 3, isn't it and the grain is probably rice, but I can't parse it either.