RIC vs SFC
This really beings on the Amtrak Guest Rewards Forum, where plenty of actual users of this connection would also have had ready answers.
Richmond works fine and is an easy transfer opportunity (self-explanatory when you get there), but there are few amenities. The BART fare will be higher and the Amtrak fare slightly lower than SF.
Another option is to take BART to the Embarcadero station in San Francisco, and to walk down about 1 to 2 blocks to the Ferry Building at the foot of Market. There, in an adjoining building on the south side is the staffed Amtrak station for San Francisco (SFC), with waiting room and restrooms.
Amtrak buses also pick up at the Hyatt Regency (Financial District stop), but there you would wait on the street; there is a sign on a post saying "Amtrak bus"). If there is a bit of transfer time, wandering over to the Ferry Building makes sense, and there are all the gourmet items for purchase in the marketplace there.
The disadvantage with SF is the intermediate bus ride to Emeryville.
But, both concepts are workable.