I log ALL game-plays under the main game & never under any expansion.
I rate ALL my games after one play & then re-adjust as I get to play them more.
Also regarding ratings, in my opinion, no game should ever really deserve a 10, since no perfect game exist, but I believe in the principle of the rating system & will therefore always strive to have only ONE game in my collection that I rate a 10.
Games I have marked as "want to play" simply indicate that these are games I am currently looking for more players/groups to play with locally. I of course want to play ALL my games, otherwise why would I own them :-)