Java is a platform independent programming language. So you can use the cab Network Manager under any Java-capable platform supporting TCP/IP e.g. Windows, Linux
No, you cannot. The minimum requirement is 1.6/6.0 since cab Network Manager v3. Java 6.0 offers a lot of new features we are planing to use and Java 1.4.2 and 1.5/5.0 are outdated and at their end of software life cycle.
cab M-Series printers are supported since cab Administrator v2.0.2 or cab Network Manager v2.4