Any thoughts on part 2.) rotating wide narrow panoramas to get the greatest width from the paper?
Yes, that's easy too: rotate the image in the editor. See screen shots below, editor rotated 30deg and page preview. I got the angle by trial and error but you could calculate it. The image used was just a cropped version of one in a recent folder.
Again, fit to page with auto crop off was used.
The new measuring tool in the page editor enables you to check how much advantage there is in using the rotated image.
In the one shown the overall length increased by 20mm (~3/4") on A3+ paper. That's only 4% - is it worth it? Using a non-rotated image I could get 3 prints on the one page!