I don't believe that one should be more restricted than the other. I generally disagree with the notion of movie ratings. Just provide basic warnings of what potentially offensive material films may contain and leave it at that.
Exactly.
Most {Commerical} movie violence is cartoon violence anyway; so I doubt it could offend anyone who hasn't the life the most sheltered life.
Even real violence is more accepted on television/movies than sex/nudity. Compare reactions to Janet Jackson's bare breast in the 2004 Super Bowl versus a brawl breaking out on live television.