If an upgrade my subscription plan, will the domain name for the form's link change?

2.  When I purchase this product (I think we are doing the professional) does the domain name change again?  I noticed your example showed both a http://submit.jotformpro.com and an http://submit.jotform.us

I believe if you upgraded to a paid plan, the existing form URL and the edit links you are using will not be affected and should still function as how you have set it up. 

If there are any changes in your subscription plan, where sometimes Premium/Professional will be using the domain name jotformpro.com, the changes should only apply to new forms and should not affect your previous form links.

I hope that helps. Please do let us know if I misunderstood your question.

Thank you.