C4C Tenant copy

I need help with following two items around C4C:

1. What are the restrictions of restoring one tenant with the restore point of another tenant? Meaning can we take a C4C prod tenant and restore it on C4C QA tenant. Basically C4C system refresh from Prod to QA.
2. What are the restrictions, in hybrid mode, that would prevent us from connecting a tenant that has been loaded via one set of on prem-systems e.g ECC prod to another set of on-prem systems e.g QA ECC, where the name of the on-prem system needs to change on the C4C side?