Implementing FB log in

I've created a facebook profile for my domain a few weeks ago.
Now I want to implement the fb login application.
But since I need a personal fb profile to create a new app I'm a bit worried.

Are there any disadvantages, if I use my private fb account for this purpose?
Will my forum or any AddOn be linked to my private fb account then anyhow?
Thank you @Brogan
Now I got another problem:
One or more of the given URLs is not allowed by the App's settings. It must match the Website URL or Canvas URL, or the domain must be a subdomain of one of the App's domains.
My domain is something like
So I also used this and tryed to log in via that site.
Is there anything I'm doing wrong?
Is there a solution?

Best regards!