Skeletally, the projection of the chin itself, it's OK - or better! I'm not sure how good a result you'd get from genioplasty because your chin already has projection and you have a significant sublabial fold already. If you go for it, then it needs to be more vertical and only slightly horizontal. You might want to throw in a little lipo as well, if you're genetically predispositioned to carry fat there. I was (had loads of fat even at a US4) and the results were really good
It is not the chin but the lower jaw that looks recessed to me - but only a little. Worth undergoing full bimaxsurgery for? Hmmmmmm...not really IMO but it's your face Can you open the bite without surgery? (I think it makes sublabial folds worse)
WRT surgery, the largest movement that's commonly done in BSSO is 10-11mm (and people can get a further 5mm from genio). The smallest that comes up is around 5mm (below this, there's not that much point doing it) I'm guessing that if you got bimax, your movements would be on the lower end of that scale, the bottom would move forward about 2-3mm more than the top, and they'd throw in a little CCW