I am a bit of a newbie as well but I just so happen to be playing around with window layouts right now and I think that's maybe going to have to be what you use.
So you will create a column layout: 2 columns, one for your panel showing functions and/or classes and other with the original sublime view.
You will need some global state so that you can keep track of which views are for your panels and which are not, so that you can create an on_query_context() method which returns true if you're operating in one of your views. I assume you would want to click on the items in your panel and scroll the other view in place for example?
Let me know if this makes any sense. I am not sure about it but I think it's doable.