It's not a good sign when the port test doesn't work, it can mean that an ISP is blocking certain ports. I can't find any info to say that Cable One block p2p but apparently they do shape p2p bandwidth.
Try changing ports. In LW tools > options > advanced > firewall config. Change LW's listening port to something in the range of 49152 - 65535 (eg 65000) > apply > ok. You can try any ports in this range.

A few people have said that there was no gnutella.net file within their preferences folder. If there's not one there, just copy & paste the file that you downloaded into the LimeWire folder anyway. Remember, LW has to be properly closed at the time.

You could also try port forwarding for your router. The instructions are here.
Port Forwarding for the Netgear WGR614
Don't forget to set up a static IP address first. LW's listening port, port in the 'manual port forward' box & port forwarded within the router setup should all be the same number

You could also check with the building's manager to see whether there's any firewall associated with the apartment complex's internet setup.