Can I use the same CCF GUI for both ScrumWorks Pro and Quality Center integrations with TeamForge?

Yes. Get CollabNet Connector Framework 1.5.0, and the latest version of the CCF GUI from http://ccf.open.collab.net/update-site.

For the same TeamForge site, you can run a Quality Center as well as ScrumWorks Pro integration using two landscapes and a common CCF Core database.