What happens if I transfer Domain Name?

Dear DASP,
I've read through the forum and found some answers to my questions, but not sure I have all I need, so please allow this post to hopefully make it clear.

My site at DASP is www.cfdresults1.com. Last year I had to use www.cfdresult.com, which is hosted at NS. Without going into any detail, updating the database with real time Contestant results, multiple times per day, was a nightmare using NS. It is much easier and nearly painless at DASP!

Here are my questions.

I would like to point my NS domain, www.cfdresults.com to DASP. Specifically:

1. Is there an additional cost(s) to have a second domain under my current plan?
2. Will I be able to access and manage www.cfdresults.com, the transferred domain, using my same login as cfdresults1?
3. Is it possible to turn off www.cfdresults1.com after transferring www.cfdersults.com to DASP?

I would appreciate a quick reply as the site must launch July 22nd. (Don't worry, it's 95% built and tested.. )

Many thanks,
Brian