You don't need to run the mew relay to add a custom node. Let's do this.

Step1: run geth with rpcaddr "0.0.0.0" 
Step2: redownload the latest dist.zip from GitHub
Step3: open the index.html file click on the node switcher click custom node. For the URL type http:// < your remote IP > now click add. That's all you need to add a custom node. At first I thought you are trying to get the mew_relay to work. :) We no longer require the relay to add a custom node. Let me know how it goes.