I'd have to recommend Final Cut Pro. Really good program (after you recover from the price). As was hinted to above, if you want to learn the animation thing, it's goind to take a bit more time than you may suspect. Compositing can get pretty elaborate... It is a blast, though. Curious why your blue-screening didn't work in Poser. I've had quite a bit of luck with it. Maybe I could help. Of course, there's also Alpha-Channels... Let me know! Bets of luck.