Q. Can a Production Defender License be used to set up a server in a development/lab environment?
A. Licenses are domain specific. So only if the domain name is the same.
Q. Can the Security Server, Web Interface & PowerShell components be installed on the same server?
Yes. There are no limitations on where components can be installed, as long as system requirements are met. Please refer to the Release Notes for your version for the applicable system requirements: Defender - Technical Documentation
Q. Is there a way to assign a specific software token serial number that someone is already using in production to a development deployment?
No. You would need to generate a new token in the development environment.