License transfer requires active Extreme service contract. If you don't have it, then Extreme most probably will not transfer them. But still you can ask your local sales representative.
Secondly RFS4K has already 6 licenses on-board. They are not transferable as they are tied to hardware. If your RFS died, then (assuming that you have active service contract), Extreme will replace failed RFS for working one which will contain 6 licenses on board, and will transfer all additional licenses you had on broken one. In total you will get what you had before.
About licenses question. You cannot transfer 10 licenses as you can only have packs of 6, 12, 24 and 48 licenses. So you cannot have RFS with 34 licenses as you cannot divide it by 6. It's just a math.
To check what you have, go to CLI and run command: "show licenses" and I believe you will see few license keys there, as you can have one key for 6 AAP, and other key for 12 APP and so on - all of them on on device.
In short, yes - they stack up. Up to the supported limit, which for RFS4K is 144.
Adam
