Nice ride. Pretty cool. No expert but I do not think a leaf spring drag is a good idea. Have you looked at making easily removeable wheelie bars? Depending on how much throttle is needed to wheelie, you might look at a throttle stop. Or add about a 100 lbs. of removeable weight to the front.
Whatever you decide on I think a roll bar and 4 point harness is not a bad idea.
Can't speak for anyone else but I'd love to see more pics.
