That is so weird that you guys are having problems with the figure not sitting on the seat. It's all about how you pose the figure, how far you bend the knees and how you position the ankles and hips - some tips on that: the knees may have to be rotated out to get maximum bend, the hips can go as far as you want, don't let the hip boxes get in your way as they will move if you tell them to.
The stand seems to be set to hover the bike just over any figure's head, that is about twice as high as they flew in the movie but it makes more display potential possible. The stand is designed so that the bike is horizontal when set to a banking angle, and slightly upwards when not banking - I think the best angle for display is about halfway into that bank, it brings the nose up in a way that makes it subtle for a superior display.
It's currently the main display on my desk, just it and the Planet Express Ship and the HMS Bounty Klingon Bird of Prey Micro Machine, and that TVC battle droid I keep observing for wilt.