Edit : I gave it a few minutes after restarting Nginx and it looks like using the files from Github was my fix, looks to be that everything is working now!
After doing a git clone of the current repo and building with the Dockerfile as opposed to just using the currently available nodebb/docker on docker hub, it looks like those issues went away. It currently isn't displaying anything at all right now, but in the logs I see:
nodebb | Starting NodeBB
nodebb | "./nodebb stop" to stop the NodeBB server
nodebb | "./nodebb log" to view server output
nodebb | "./nodebb help" for more commands
nodebb | NodeBB v1.12.0 Copyright (C) 2013-2014 NodeBB Inc.
nodebb | This program comes with ABSOLUTELY NO WARRANTY.
nodebb | This is free software, and you are welcome to redistribute it under certain conditions.
nodebb | For the full license, please visit: http://www.gnu.org/copyleft/gpl.html
nodebb | Clustering enabled: Spinning up 1 process(es).
nodebb | 2019-04-04T22:33:50.921Z [4567/22] - info: Initializing NodeBB v1.12.0 https://forum.mysite.dev
nodebb | 2019-04-04T22:33:54.634Z [4567/22] - info: [socket.io] Restricting access to origin: https://forum.mysite.dev:*
nodebb | Thu, 04 Apr 2019 22:33:54 GMT hsts deprecated The "includeSubdomains" parameter is deprecated. Use "includeSubDomains" (with a capital D) instead. at node_modules/helmet/index.js:33:28
nodebb | Thu, 04 Apr 2019 22:33:54 GMT hsts deprecated The "setIf" parameter is deprecated. Refer to the documentation to see how to set the header conditionally. at node_modules/helmet/index.js:33:28
nodebb | 2019-04-04T22:33:54.961Z [4567/22] - info: Routes added
nodebb | 2019-04-04T22:33:54.969Z [4567/22] - info: NodeBB Ready
nodebb | 2019-04-04T22:33:54.976Z [4567/22] - info: Enabling 'trust proxy'
nodebb | 2019-04-04T22:33:54.986Z [4567/22] - info: NodeBB is now listening on: 0.0.0.0:4567