Excellent info here, thanks!

Are there any nuances to be aware of re "buying" an award flight for a relative?

For example (and correct me if I'm mistaken), my RR points can book an award flight for my sister no problem and have benefit to her even beyond the money she would save due to the flight now being completely cancellable without risk. Now let's suppose the one-way cost exceeds 9600 points. What are the caveats to weigh re converting the points to a certificate first?

1. The cert will have a one-year life.

2? Will the cert be permanently assigned to my sister? Or if she cancelled (the flight booked with the cert), would I have use of that cert later?

3? Other nuances that differentiate from RR point redemptions?