The Dragon capsule was designed for 7 astronauts so there is plenty of room for everyone. The Russian crew wouldn’t have seats so they would have to strap themselves to the floor or something. Probably a rough ride but better than dying.
There are no extra seats for 3 more people plus suits
Story Musgrave stood behind the shuttle commander on one of his re-entries. He wasn’t strapped down. Since he had an inquisitive nature, he must have wanted to find out how re-entry would be standing up.
Correct, and regardless, the rescue Dragon wouldn’t have to launch with anyone aboard, but come back full.