Do I have to use your set of IP ranges?

Technically yes. You can change the IPs of the servers if you wish, but it is not recommended. If you do decided to use a different range you may find that certain functions stop working and to fix them you will have to edit the Karoshi configuration files. We will try our best to help solve any problems that arise with the edits, but an acknowledgment that our main priority is to help those using the standard default system must be had.