Since a large amount of this post have been made happily redundant by MSV-Gearhead and his excellent Q&A, I'll just leave the one point about rating gametypes.
Rating maps should be smarter.
The game needs to record rating based on game type as well. For example if a map gets rated 5/5 on every capture the flag game, and 3/5 on team death match, this should be reflected in the stats, when selecting what game type to play on a map, I want to be able to see how high each game type is rated, and which game type is highest rated on this map, as well as the general popularity of each, and then choose what to play accordingly. This would mean that maps are seen in there best light more often, and make playing new maps more fun.
If nothing else, knowing just the highest rated and most popular gametypes would be enough.