Thanks for choosing X!
Yes, that is right. You might also want to check out DesktopServer if you want to initially start building the site locally as it has a Wordpress blueprint so installation is easier and faster and you could also get a local URL that you can use to validate the site locally.
There is nothing to worry about. You could attach two URLs for each license. One for the development/staging site which is in your case the site you will build locally and the live/production site.
You can find more information about the Theme Validation here:
Hope this helps.