ftp.domain.com is a hostname for an FTP program. To me, it sounds like you are trying to access it in a web browser.

Do you have an FTP program installed yet? If not, when you install it, it will ask you for a Hostname. Then you will use ftp.domain.com in there, and it will work.

And the last couple of times I've tried to access my control panel through GlowHost, I've gotten a page reading
Can you tell me what you were trying to do? Were you trying to do like http://glowhost.com/cpanel instead of http://yourdomain.com/cpanel ?

Or were you trying something else, like the login area inside your MyGlow account manager, or the login thing, here?

https://glowhost.com/login/cpanel.php

Please explain in detail and we can have a look to see.