Rubber Chucky, don't you have any pioneers in your family tree? Just wrap some electrical tape around the area. There's 2 Phillipshead screws to loosen so you can move the perch back some, then push it back over the tape. This will slow the movement, but not stop it completely.
Unless that's where you rest a hand when doing pull-ups on the handle bar- so what? It's stationary enough to get the job done.
Clutch lever; huh? It doesn't m,atter whether you pull it back too far. What matters is if you get the point of engagement at a good place. Just put new bars on and I'm going through this myself. Unless the lever is hitting something like a bar-end mirror, I don't get what's going to prevent the lever from going all the way back. HOWEVER- you can easily adjust the clutch so the lever doesn't have to come all the way back, anyway.