not so much as stupid but more or less a way to let naruto continue on to capture/fight sasuke

and alot of the time naruto isn't using much of kyubis power the seal prevents it and only allows a lil bit out at a time

so rock lee should be able to handle himself especially if he gots his speed back

and i wonder what would have happened if naruto did get hit with kimimaros bone sword i bet kyubi would have healed him and more chakra would have come out