So I finally got around to giving webstorm a spin, setup the correct runtime, installed the netsuite plugin, and was suprised to find that SS2.0 autocomplete / intellisense was working out of the box. But it was giving me some odd recommendations:

context.request.method == http.Method().GET()

That's not right, and the script fails. So I also downloaded the SS2.0 api javascript files and started to override some of those definitions so it becomes:

http.prototype.Method = {
  GET: "GET", 
  POST: "POST", etc
};

And now autocomplete / intellisense will prompt correctly:

context.request.method == http.Method.GET

Has anyone already gone through this exercise and corrected the SS2.0 api definitions? are they available anywhere online that I could just grab?