1. I don't see why there would be. AE is a video software, whereas Catalyst is not.
2. That could be nice. Perhaps a way to export effects out of AE as FXG and then import and use them in Catalyst and Builder.
3. ?? What would you need to do with the video in Catalyst besides build a container for it?
you can bild panels scrolers and so on based on video clips and it can look realy cool. while now you can build a prewiew in catalist and than chenge elements to videos in fb.
your site/app back can be video clip menu appearing could be made from a video... at least states transitions can be video bazed...
http://gotoandlearn.com/play?id=67 watch it..
my point is if you want to build a cool interface fast you would base it on video clips.. easing of interaction and jumps back forward from catalist to video pruduction product would be a time saver.