Is he a manager or what? Why can't he get a user permission on his laptop to install the CMS?
Next you can try: connect through web browser.
Splitting video signals is a very complicated thing. If you just connect two DVR inputs in parallel to the same camera output, there will very probably be some interference. To get clear picture you must use video splitter amplifiers (1 IN - 2OUT) for every DVR input.
If you have cat5 cable with video baluns, it's not Ethernet. It's just the same cable type , simply using twisted paired wires for signal transfer and that's all.
If it was a professional company that did the cctv install my company's IT would have no problem with CMS software.
But they wont allow untested software on their servers sadly.
Adding a bnc splitter will just get messy i was hoping there be some kind of rj45/cat5e/ethernet duplication amp device, a 8:16 split, but i can only find such a device for bnc.