Q3: Why does the thumbnail map render as a static image when viewing pages, but is interactive when editing pages?
A3: On Wikipedia, and most wikis other than Wikivoyage, the emdeded thumbnail is a static map, and the full screen map needs to be opened before the map can be zoomed or panned. This is for for performance reasons, and to present some content if javascript is disabled, and for printing.
That preview mode shows an interactive map is a bug,
phab:T203863 (and also a performance issue). Further explanation can be found in the comments on
phab:T202793.