[gardobus]

You can always return to stock in like 5 minutes. There are stock backups available for download in various places. So don't let that worry you.

As far as making backups, they are easy. You don't pick out files or anything, it is all automatic. You boot into recovery (hold X while booting) and then choose the option to make a nandroid backup. It's as easy as that.

And as far as Froyo goes, a rom version was just leaked out. I'm currently running 2.2 with Flash. See why rooting is worth it? :P