Ah.. the "letter" issue is one I see at home with a K5400... It's network shared direct to my machine (not through a server)... For some reason my machine starts with letter initially but a laptop also direct connected is seeing it as A4 from the get-go... Still trying to track that issue down.
IT appears that even though our script is set to delete and reinstall the printers that the settings are not being reloaded off the server each time, ie all printers set to A4 but are defaulting to letter after logon. Guessing it's being stored in their profiles somewhere?