I agree on both except I think the reason they will keep Carr is just because if you get rid of him this year you won't have any money to sign anyone in free agency. I don't expect them to be big players in free agency, but I do expect them to want to add a few key guys that Moore likes and wants to help establish his team.
But, I do think if you are going with Rattler, or another young QB, you commit to them and at most you sign a cheap veteran QB just as a mentor.