This one is straightforward. After restoring a system using system restore, are registry keys and data get restored as well?
Interested in Win7 only.
Yes, system restore keeps and restores backup copies of the registry.
In fact, the registry backups can be used without system restore if your system has a corrupt registry. They are stored in the "c:\system volume information" folder.
Microsoft documents the procedure to restore just the registry manually here: https://support.microsoft.com/en-us/help/322756/how-to-back-up-and-restore-the-registry-in-windows
Yes, there are restored to state when selected restore point was created.
Be sure you have drive C monitored by system restore (Volume Shadow Copy).
The Registry is part of the SystemState and is backed-up as well as restored with it.