*Does NW sell international upgrades like UA does? Does V class qualify for a paid upgrade if there are seats available? Right now flights look overbooked in coach but lot of seats in biz.

NW does on occasion sell upgrades at check-in but is unpredictable. Search the NW forum for a thread on this.

*Will they OpUp skyteam elites?

Op-ups go to NW elites -- but of course it never hurts to ask.

*Can I make it through MSP to my ATL connection, clearing customs, with an hour of time? (Arrives 540PM, leaves 655PM)

Yes, should be no problem

*If that isn't enough time, will I have any grief getting a later flight out either that day or the next day without paying any additional $$$?

Yes, they'll put you on the next available flight without charge.

*How's the food and service on the A330-300?

Service is usually fair, sometimes good other times marginal. Food is fine, not great but certainly edible. Enjoy the IFE.