I would highly, HIGHLY recommend that if you do develop a plugin, you use the HTML bridge capabilities in the SDK as much as possible. This will probably simplify your coding experience. We also recommend that you use angular if you're using any javascript framework.
Basically the bridge allows you to embed HTML pages within their own view in Web Client. You can also add things like additional Actions, or new Objects without Flash/Flex code, because most of these things are defined elsewhere (XML I believe, but I'm not a developer).
The code samples for "global view" and "chassis-app" are good examples of what you can accomplish using the HTML bridge, and probably good examples to follow in general.
