The downtown is decent for touristy stuff, they have a very nice strip with trolley's and outdoor eating, and such - pretty much what you'd imagine for a brainpower center of the US = clean, nice, etc. Whilst wandering the downtown, you may discover the many, many Peanuts character statues custom painted and left about as a sign of hometown pride (Charles Schultz was there). I've taken several pictures of them, sometimes posing in them, if you are into that kind of thing.
Knowing you like hockey, I would have suggested visiting the MN Wild, but alas with playoffs they are on holiday as well. I'm sure you knew that. Speaking of which, they'd be housed in St. Paul if you cared to visit the arena - will you be with car? Or restricted to MN foot-travel and public transportation? There are a lot of things to do outside of the city limits as well, depending on your ability to drive around, even with minimal spending.
You mention not having time for the bars....the city has a very high population of gays, and without any comment for or against on my part, I'd simply pass this along for your own decision making should you wander about at night and decide to spend any time in a bar - know what you're heading into and if it matches your tastes. I found this out on my second trip to MN on business, when I landed in the middle of the Gay Pride parade and celebration unexpectedly.
There is also several very nice park areas following along the Mississippi river.
Meh, if more comes to mind, I'll come back - I'm about 3 yrs removed from my trips there, and usually I was located about 20 min north of the city
