You don't need a static IP address, here's how you use your WHM (web hosting manager)
1) NEVER EVER assign an IP to a domain unless you have a static IP address (which most of us do not)
2) The package comes first then you create an account. Multiple accounts (domains) can use the same package but it's important to remember create the package first THEN create the account.
3) While creating the package never leave any field with UNLIMITED, change it to a number value.
It might be messy moving yagt.org to thrillhost since it was an addon domain ... also I do remember a while back advising you get a REAL resellers account instead of using the messy cPanel addon domain feature. If you had a resellers account from the start it would be very easy to move yagt.org. So told ya so
I'll call you this weekend and try to help you out with your questions.