Very nice first review! I'd say I agree with you on almost everything.
Almost meaning I'd give the Multiplayer with everyone in the same room with you a perfect 10, because it does everything the single player one does, but I'd give the WFC multiplayer a 7 or 6 because of the fact that you can only do races, you can't choose from every track, and it takes what seems to be an eternity to find people. (Yes, I give them some slack as this is their first WiFi game, but I don't like waiting for about 5 minutes, just to find that I can't find any players).
Also, I think the graphics are a perfect 10, but that's just my opinion.
I see that you have the Bleach game listed as one of your friendcodes... I've always been curious as to how it is, if you do another review, I'd sure like to read one about that game :D