Only one profile to a game. It's been forever but you register a Mii to the profile at some point, and that's the name records are saved as, and I'm not sure there is a way to change the Mii. Single player game modes include Grand Prix, Time Trial, Ballon Battle and Coin battle. GP is exactly what you would expect, Time trial is made suprisingly robust by Street and spot pass, and I haven't spent a ton of time in battle mode. Havn't played in local multiplayer Online includes the full suite of 8-player race and battle options, and its pretty easy to find a match. Communities have been largely ignored, but they were pretty pointless to begin with. You can see any online friends playing Mario Kart 7 online through the online menu or the system friends list, which both give you the option to jump into their game. The in game menu also let's you see and join up with recent random players IIRC. As for online VS retail, that really depends on how much use you intend to get from the game. I wish I had the digital version myself, just so I could always jump into a match without needing to go find my game card. If your just going to beat the GP, play a few online matches and shelve the game, than you would probably prefer physical media.