Newbie: Questions about Installing Parallels after Boot Camp already installed

I have tried to find this on either the forums or on the Parallels documentation, but can't find a straight answer on my questions:

How difficult is it to install Parallels after I already have Boot Camp installed?
Do I end up having to call Microsoft to get my Windows XP reauthorized?
Will Parallels just run off of my Boot Camp partition (i.e., I only need hard drive space to install the Parallels software)?

I'm really thinking about buying Parallels, but if it's going to be a pain to install it (e.g., having to uninstall Boot Camp then reinstall it), I made hold off until a newer version comes out. Thanks in advance!

 

Installing Parallels is easy. Very fast. Get the RC2 Beta.

Yes, you'll need to reactivate XP through Parallels. But that's the last time you'll need to do it. They fixed the constant reactivation problem.

Yes. You can run your Boot Camp Partition in OSX through Parallels now.

 

RC2? Where?