The design appears to be optimized for users who want to transfer all their domains in one go, with all 245 domains (as per the system limitation) pre-selected and no option to mass-deselect.
If a user wants to test your system by transferring just a few domains, they must manually delete all the other domains from the list by repeatedly pressing X.
The majority of your users will transfer domains to you as and when they are due to expire at their current registrar, probably in monthly batches. That is simply how most people operate, putting off an expense until it is due.
It would be handy if your columns followed the convention of having a tick box at the top which allowed the user to mass-select or deselect all the domains. Also, listing them in order of expiry, rather than alphabetically, would make the whole process far simpler and quicker - see the Request for Sorting by Expiry Date.
Again, the ultimate interface would be if we could simply type the domains we want to transfer into a text field. A good format for this would be:
… your system could then run the necessary checks and remove any domains that do not have an eligible TLD etc.