Get ready for a long process. You pretty well covered the list of things that can be fiddled with. Start fiddlin'. But be sure to change just one thing at a time, try it, decide if it helped or hurt. If it helped, leave that and try a different part. If it hurt, either put it like it was or move it the other way. You may find that after you get your seat dialed in and then change your handlebar tilt, the seat is wrong again. After about 30,000,000 combinations, you'll either have it all dialed in or go nuts and start buying replacement parts - or both. But don't distress, it's not as much fun as it sounds like.
