being that low your bike has to be a teeter toter on speed bumps....
As far as slipping the forks I do over tighten them but by no means am I crushing the fork. I am only use a 4" Allen wrench and that is it. Slipped my last set of R forks and put a couple thousand miles on them and didn't have them slip at all not even 1mm and that was even with hardstops, pot holes, wheelies, and crashing the bike.