Unfortunately, I only have the experience to answer two of these questions...
Do not refreeze the rat. This is unhealthy. Plus the frozen rat pinkies are cheap enough to toss away if not eaten.
A good site for Ball Pythons? You've already found it. This site is overflowing with all the knowledge you would need...or care to have.
I should applaud you on your early research. Too many people buy an exotic animal only to worry about care afterward. You are learning about the animal first. This is how it should be done. Congratulations, amigo!
Chris =)
-----
(insert something profound with a touch of humor here)