We have a small chat app built using GWT/JS and we need to deploy those files into openfire HTTP server for maintainability and because the cross-domain security.
If you want to bind to a different port than what Openfire is using itself, you can simply create a new Jetty instance, following their embedded server guidelines.
Running on different ports than the HTTP Binding / BOSH interface is likely going to give you some issues. As @akrherz pointed out, I created very similar plugins recently. You could look at those for inspiration.