Sorry for not getting back to you guys in a timely manner, I don’t have any notifications set up right now for the forum.
I don’t have any sites that have users that aren’t WordPress users myself, so I hadn’t really thought about it. I’ll look at how buddypress works and see if its possible – I think that could be a good feature ??
I like the post rating idea – I don’t know how well it would work in practise though, There might be code problems with doing it though. I’ll add it to issue tracker as a potential feature ??
An API seems like a good idea and it’d allow a lot more customization for people. It would be pretty useful for people who wanted a particular item used for experience, such as the rating. I’ll take a look at designing a solution – but it probably won’t be coded for a while because it’s a big architectural change.