Star Alliance - Earning UA miles on SAA Metal, VS codeshare

I have an upcoming flight booked through VS and one leg is an SAA codeshare (SAA metal just for that one leg). Can I earn UA miles on this flight?

Should I keep a VS mileage number on the reservation and then give my UA number to the SAA gate agent immediately before the SAA flight?

Yes, you can earn miles on your UA account; the operating carrier is what matters.

It doesn't really matter when you get your UA FF# put on the record so long as it is there when you take the flight. You should also see it printed on the BP; that's your indication that it is as correct in the system as you're going to be able to make it.

Do save your BP until it actually credits, just in case.