No. No simultaneously use
FM Server will use port 5003 for client access - both, FMS11 and FMS14 (among others)
I agree with Markus.
If you are desperate to run it from the same computer you can try to run FMS on VM running on the same server.
Agree with Nicolai, if you MUST do it, do it inside of VM so both of your servers are isolated from the other. This will also be important for addressing DNS conflicts.
true. Via VM, it should be possible. I would not run this configuration for production - when the VM is running on a user's machine..
Using virtualisation, it's common to have several virtual machines running under one single hardware