For real faster rendering you'd need the engine to render the window, as in GED.
Yes. And if WED is to be useful as a tool, then the engine should render in the perspective window, as in GED. I realize that GED has it place (and, frankly, I still need to test it ... perhaps later today), but it just makes since to have ONE editor (not WED, GED, etc) to create and/or put together your level, level lighting, entities, etc.
