You seem to have everything pretty much worked out... I tried to think of additional suggestions but couldn't really come up with anything much.

One place that did spring to mind for your Bavarian road trip was a place called Hindelang - where we went for hiking holidays when I was a child. I've just looked it up, and it looks like it hasn't changed much. It's not very well known outside Germany so is unlikely to be overrun by tourists... maybe that's the sort of thing you're looking for?

I'm afraid I can't help with any of your other questions...