Now very soon I shall be replacing the server where all my software installs are located. Is there a way to change the source path? Or do I need to totally fake it by moving the install files to the new server, remove the old server from the network then create a DNS alias with the old server's name and point it to the new server.
Secondly. When I get an upgrade to a piece of software I deploy it as an upgrade (at least according to GP, realistically all upgrades are effectively new installs). Can I remove the old GP deployments (selecting "Do not uninstall software, just prevent new installations" to prevent complications) then delete the install files to reclaim disk space.
On your first point, there is no way to change the path that I know of. It's for this reason that I always use a DFS path when deploying software. DNS alias might work but I'd test it in advance to be sure that authentication doesn't get it's knickers in a twist.
Not too sure about your second point as I never deploy anything as an upgrade.