1. no, as long as factory made
2. no but must have a minimum of 2 brackets holding it on, and must be secure
3, not sure but dont think so
4. good indication that car not stock. don't be lazy and wash it.
5 yes. a big yes. if hidden well and don't give them a reason to look, shouldnt be a problem though
6 as long as it is recirculating it should be ok
and become a member of SAUWA