The "Yes" for number 2 was, sadly, in response to the "Dreaming too hard?" question. Tectonic generation has been on the wish list for a long time but isn't likely to get implemented soon.

Placing markers, text and vector graphics onto FT maps has also been on the wishlist for a long time. That's more properly the domain of the Campaign Cartographer line of tools. It would also take a pretty significant amount of effort to implement and isn't likely to make it into the product soon. It's one of the problems of having a single part-time contract developer on the project: there's not a lot of time available to do the work and the complex features are more likely to get pushed out.

There has been a request for SVG output as a common vector format. Do you think that might meet your needs?

The multi-file export misfeature was an idea from version 1.0 about 12 years ago now. I was never particularly happy with how it turned out, but it seems to work well enough for what many folks seem to want from it. It really doesn't work well for stitching multiple files together, as you found out.