Hi,
1. Just contact "Licensing@cisco.com", they can re-host your licenses. They'll ask you for some details I guess about the existing licenses and also you'll have to provide the new MAC's of the machines.
2. Yes, you can.
3. Don't think so. It's better that you upgrade.
4. No, everything's should work smoothly.
he only thing you must do is to create a PTR record in your internal DNS that'll point to your Expressway-E internal NIC IP address. Depends on the deployment of course:
- Single NIC = Create a PTR that'll point to the PUBLIC IP address of the Expressway-E.
- Dual NIC = Create a PTR that'll point to the internal DMZ IP address of the Expressway-E.
If you won't do the above, the MRA won't work.