Although you have a point, What buildings besides Gringotts are tall enough to block out Hogsmeade. Gringotts is too small to block it out for the entire area.
Touche
Yes, but the details wouldn't be
as wonderful, since so much of the visual effects would be compromised.
--- Update ---
She would allow it, as long as it was anything besides Hogwarts and Hogsmeade. I love how you guys are always saying I make it seem like Jo vetos everything, and yet one of the things she wouldn't veto, you guys think she would.

And I think people would much rather view DA than nothing.