Thank you for your post!
The information you listed shouldn't be required. What you can do is use the IP Address to access your FMCloud Console. Go ahead and do the import process there. You will receive an email that should explain how to update the CNAME record for your domain. If issues continue with this process you might Contact Support.
I hope this helps!
I've also just realized that I thought I could use the AWS SSL via their certificate manager for FileMaker Cloud but that doesn't seem to be the case--which was partly what was confusing me.
Will acquire the SSL from elsewhere and give it a shot per your instructions.