Escuan, I have also found this hard going but have finished a few minutes ago.
Your queries:
18 is what Don Manley calls a charade: 'ruined primarily' + 'on account' (with one letter surplus) + 'evil' + 'SS';
30 is thematic (the partial def is the last word);
33 is thematic (try Google for some examples);
5 is thematic (which should make you smile!);
13d is thematic (think methodically).
But I'm as stuck as you are on 9. I have the word, which fits the def, but can't parse the clue at all apart from the obvious partial anagram.