It's about self-awareness. If you and the people you're ripping know that you're doing it qua rivalry and that you really would enjoy having a beer with them, it's cool. If you genuinely think opposing fans are inbred rednecks (Alabama fans excluded, since they are), it's an issue.
Everyone I saw seemed to be on good behavior Friday night. Only real conflict I saw was a guy claiming someone kicked his car. That almost resulted in a full-blown Royal Rumble between two groups of guys. NC State folks seemed like good people. Nothing like Maryland fans I encountered last time I saw the Vols in the Dome.
Depends on how big and gaping the target is. No way is there going to be any actual physical contact, but I'd firehose a good buddy from afar. (No pun intended)