I have fixed this by going with Arend's suggestion of getting the information that I need from the registry. So the productsuite, @domain variable (for whether I want netbios or FQDN domain) and determining if server is a DC or member server has been solved by using the registry to return the information.

So this is not as much of an issue as I thought. Probably is better to use information direct from the registry anyway so as not to be reliant on specific Kixtart version.

However, it would be nice if the syntax for adding a printer and deleting a printer was addressed in future to ensure consistency between the two commands. But again, not a huge issue as it does work.