Obviously without knowing the specificities of the game can't make too much judgements, but given the "drugs in a positive manner" thing is pretty much on par with the rating refusal of Fallout 3 (incidentally you can thank Oz gov't for having the proper in-game drugs like Med-X) we can guess there's something about IRL drugs being used with positive in-game/story effects, which is generally frowned upon. It'll be an easy enough tweak tbh, just a name change and given the kind of game it'd probably suit it to have something silly. Dunno on the sex stuff, I'd guess handled quite badly storywise I guess to not get away from the "obscene" element by being "artistic".
As for stealing cars, shooting people, trespassing, tend to have repercussions such as cops/army showing up and such, it's rarely if ever presented as a positive act.
(p.s as far as jaywalking goes that's one of the things I had to look up a while ago, didn't realise in America crossing the road could be considered illegal . Which I guess also just goes to show what might be considered okay in one country isn't in another)