Cast/Crew is copied by opening the Cast resp. Crew section of the Edit window, right-clicking on the Cast list on the right (what represents the credits) and select "Copy", then doing the same in teh target profile and select Paste.
Other stuff has to be copied "manually".
Of course, in your case, as you using the other profile as a base only, you could also simply change UPC and Locality of the downloaded profile, then no copying is required, only editing. IN that case, make sure to remember to adjust ALL details of the new profile according your disc (pay particular attention to the SRP).