P: Random Sorting

Weird, it doesn't for me. That's a really funny and highly un-intuitive way to do it that makes no sense. View > Sort is the ony thing that affects Impromptu Slideshow for me.

My primary need for random is grid view (sure I could put together a grid on Print or Web, but that's insane when it's a simple Library viewing task). The View > Sort menu should really be the only thing affecting anything on Library including Impromptu Slideshow.
I can't be the only one that needs to look at a grid of images in random order.

Yes.   

That setting on the Slideshow tab makes the Impromtu Slidesow (ctrl+enter) on the Library random for you?

It makes the Preview slideshow random for me.

Yes, but "impromptu slideshows" do not have a random option and take the sort type from the View > Sort setting.

Random Order is already in Slideshow