2 Questions - Power RSS + Add-on domains?

Hi,

I'm interested in either the Baby or the Swamp shared hosting.

Firstly, if I bring over my domains to hostgator, will I have seperate domains under their own right (not sure how to describe it) or will they just be add-on domains under the main account in their own subdirectory?
By the way, I Don't want Add-On's.

Secondly, I've just purchased Power RSS and hope to run it on most of my future sites. Will this cause a problem with the terms and conditions of hosting accounts with hostgator?

Thanks for any help you can give me on this. I'm hoping to get everything sorted as soon as possible.

Simon

[MachineDog]

You can make them add-on's or you can "park" them on the public_html directory. And second.. power rss? I searched google but, I don't understand exactly WHAT it does. Anything that runs on php/cgi and doesn't use more then 25% of server usage should run.