What's the need? I don't know which skin you're using, but on the one I'm using there's a BIG REPLY BUTTON at the top of each post if you want to zip straight to advanced mode, and a QUICK REPLY button below the post for a fast reply.
It ain't rocket science.
I'm referring to the default skin. Considering everyone starts with it, I think it should be a bit more straightforward/ similar to a standard forum skin.
Threaded Mode