Yes, you will have to scan your card twice for each fast pass ride you have. We stayed offsite in April without magic bands. But we have 6 kids. It was very hard keeping up with all the cards. We bought the magic bands while there and even though it was extra cost, it was well worth it. It made life easier with park tickets and FP rides. Just my thoughts.
If we're staying offsite, I know we have to wait until 30 days out to reserve FP+ but do I have to purchase our tickets through Disney or can I buy them elsewhere (undercover tourist or AAA)??