I think tattoo and ballet is a topic worth its own thread. May be the mods can spin off the related posts in a separate thread.
I am no lawyer I don't even play one on TV. I know NYPD bans its uniformed officers from wearing beards with exemption on religious ground. So I can't see how banning tattoos from ballet is unconstitutional if it provides exemption for religious beliefs but then I am not aware any religions that requires tattoos. I hate tattoos in general and especially on ballet dancers, they are distractions and could even break characters. I think banning tattoos is a valid artistic ground for ballet companies as long as it's non-discriminatory. If a ballet company institutes a no-tattoo policy, existing tattoos can be grandfathered.