My ds is 8 and has AS and we have similar problems with social stories. Dh sees them as stating the obvious, because he knows the facts/rules and can recite them. Like your ds though, he's unable to apply them appropriately and put them into practice.
Ds is convinced he knows pretty much everything there is to know and there's not much we can teach him. 
It makes it so hard to deal with him when he takes this stance and obviously this is the sort of thing than comes across to others as arrogance and therefore often gets him into trouble.
To a certain extent, we've had to start telling him that we know it doesn't matter to him whether or not he follows the rules, but that he will upset or hurt other people if he doesn't and that's simply not acceptable.
I often find its best to explain things in terms of how he would feel if something happened to him, as obviously he can't relate to/understand how other people might feel as the result of a given situation. I explain to him that we all do our best to respect his special rules so that he doesn't get upset etc (typically AS, he has a world full of his own rules that no-one else is allowed to break) even though sometimes they can be very hard for us to remember and do and that respecting and sticking to his rules doesn't necessarily make us happy, but we do it anyway because we want him to feel safe and happy - therefore we expect him to try and do the same for everyone else.
I've also told him that just because he doesn't like or understand the need for a certain rule, doesn't mean he doesn't have to obey it, particularly when its a rule everyone has to abide by in order for us all be safe or get along.
At first I didn't think it was having any effect but we've carried on sounding like a stuck record and repeating it all to him and actually - fairy steps and all that - but I do think he's started to improve a bit, so maybe its starting to eke its way through.
Rewards don't really work all that well with ds either - like you, we prefer not to use his obsessions to reward him and anything else just isn't motivating enough.
What we have found works though is to use 5p pieces as a reward for certain things. We have a list of things he will get a reward for (written with rather than for him) and when he's saved enough 5ps he's allowed to spend them on whatever he likes.
His main obsession is his nintendo dsi and he does tend to save up for mini games that he can download from the nintendo wifi shop. We have a rule that he is only allowed to go online once a month and then only with dh (we have all the password and login details etc) to download a game - of course he can only do this if he's saved enough money as well.
This system does seem to be working for us at the moment. He loves seeing the 5ps building up in his money box and as it takes him quite a while to save up enough for a game, it doesn't feed his obsession too much, but it is still rewarding for him.