I know I'm late to the party and it sounds like you got everything working. Just wanted to highlight a few things:
1) You're definitely better off on the Plex forums for Plex specific questions. IMHO the Roku subforum at Plex is especially active.
2) The only supported way of using Plex remotely is myPlex. Otherwise you'll likely end up hardcoding port 32400, doing the port forward yourself, and disabling authentication. Up to you, but not recommended.
3) The official Plex Roku channel is 100% open source. If your changes are potentially useful to a wider audience, we'd love contributions. You're also welcome to ask questions about it, either through GitHub or on the forums. Usually communication on the forums is preferable, but if it's specific to the code then GitHub may make more sense.
Happy hacking!
