Just a slight news flash. Most gopher fans don't consider the sioux/gopher matchup as a huge rivalry (since the main rivalry there is with the badgers). I would say #2 though. Most teams in the wcha by default have the gophers as their #1 rivalry.
NDSU football already took down the chances for a hockey program with their political pull in the dome situation making the dome unavailable for hockey. The original design and intention was to allow for hockey. So the story/rumor goes. If they got hockey then the school wouldn't be in any rush to go D1 (like UND is right now).
Good teams and good playoff matchups is what builds rivalries. Thus, if by some chance, NDSU had a hockey team, it would take years. NDSU would be forced to play the caliber of teams like bemidji and AA (oh wait, the sioux tied AA this year)
A little blurb on football. I had a great time tailgating at alerus this year. All i care about is the tailgating, beer, and some good football with a bison win. UND will go D1. They have to. I can't imagine watching my team playing teams like UMD and Mankato all year long. Hope you sioux fans enjoy that. It is the loss for both schools and cities that we are not in the same div.