I tend to believe that if you cheer for your team and are not obnoxious about it, most fan bases understand that. If you are blatantly being an idiot in an opposing arena, you kind of get what you deserve. We have encountered some idiots in Lawrence, my favorite is after the game when a 70 something old lady told me(and my high school daughter) that we "needed to get our team under control particularly that #30"...........that happened to be Royce White. That one made me smirk.
Have truly always had fun and been treated wonderfully while in Manhattan. Last year, while waiting in line at a restaurant on Sunday the day after the game, we ended up having a great conversation with a starting DT for the football team. He ended up coming over to our table again while we were eating to see how we liked the food (he told us what to order) and also stopped by when leaving again to wish us safe travels back to Iowa. Another year we had seats directly behind Bill Snyder and his wife at the game, we had a great conversation over the course of the game with them.
We have had numerous experiences like that over the years. We have never had a problem and always made to feel welcome.