#4 is most likely Can-Can, given that the show features a Quadrille number.
I am a firm believer in serendipity- all the random pieces coming together in one wonderful moment, when suddenly you see what their purpose was all along.
The architecture in the first picture is distinctly Northern or Eastern European, not Mediterranean, which makes Light in the Piazza less likely. (And as jarretSF noted above, it's actually a Universal film set.)
ETA that jarretSF said the name of the film set seen in the first photo is "The Court of Miracles." Could the clue be in that? Miracle on 34th Street (which is how Here's Love is currently licensed) or The Miracle Worker? Elaine Stritch comes out of retirement to do a new show, Judge Judy The Musical?