What file are you editing?
It should be html/admin/header.html
You just need to edit line 84 and replace "simplemember.com/forum/" with "contactandsupport.com/forum"
It does redirect straight here anyway.
There is no automatic way to delete members who don't have referals although in my book that would be a bad thisng anyway because you can still email them if they are in the system via the Mass Mail feature.