[Cwell the fine]

I really want to get my hands on some of the stuff in these expansions, but I've never played them before. Around what level is recommended to be able to handle these expansions?

I hate importing/exporting games, and want to have a fluid transition between all of the games as well. When (in game) is a good time to start each one. I don't want to be spoiled too much, but I also don't want to go past the point of no return and get angry.