Since you can't exactly stop the glider for the time it takes to select the subject etc not really. Can totally do it manually as long as the speeds are compatible obviously.
What is your actual goal? If you want motion blur shoot at the slowest speed you can (equalling fps). If you don't want it shoot faster. Run tests before the thing to figure out what you prefer.
Probably not many. Usual thing, nobody will ever care until an accident happens. When one does it will get checked and whether it's compliant or not may be the difference between walking with no harm or with a hefty fine.