Thanks for the links to the compound angle calculators... those angles made my head spin (it's still spinning) back when I was doing the hip roof. Looks like you have it mastered. The spreadsheets available here on the guild website are handy too, but the hardest thing with using those is figuring out which of the fifty calculated angles you need. It produces lots of angles - which one do you set your skil saw to? Ah, that's the trick.

The trick with the tongue and groove miter joint, for me, was how to hide the inaccuracies. The hole in the main roof came out spot on, and then I sanded it with a belt sander and put a chamfer on the end of each main-roof board to cover up any mistakes. But each of the dormer boards has a gap of up to 1/16th of an inch, and you can see this if you stand in the dormer and look up and backwards. I could take a picture of that too... but who wants to see the ugly view? My original plan was to come up with a piece of compound trim to cover up the joint, but the joint came out OK, so I'm not even going to put trim on it. Solid wood is a wonderful medium.