They're not approved for the atlas.

The main reason for this is that they lack proper CC3+ integration and symbol catalogs, meaning that while they might be free, it is hard to use them in a consistent manner that will let other users use maps with these symbols in them.

That's completely up to you.

The main thing I very strongly encourage when making a non-overland map, is that there is a symbol (or equivalent) on the parent map to link it to. No making an inn and linking it to a blank spot near the road on the parent map because "there could feasibly be an inn here". It is the mappers responsibility to place interesting places in their maps for others to link from, and if no marker for such an interesting place exist on the map, well, then an intermediate map may be required. So generally, the idea with an intermediary map is to make up for "shortcomings" of the parent map.

Unfortunately no. The dialogs are implemented using the dialog from the standard windows libraries, which do not have support for easy user-resizable dialogs.

Maybe they'll be bigger in a future version. They have been increased over the different versions, but that only leads to people making up longer names :)

I am guessing fewer people have the free version simply because the annuals have more reach to customers not part of the community, but on the other hand, they are free, so anyone can get them without purchasing anything.

And yes, I used the free ones for my map. They're listed among the allowed resources here (the "Free Addons" section).

Could you attach the .fcw here? I'd like to have a little look at it, and see if I can replicate the problem on my computer and have a look at those problematic polygons and maybe send it off to the devloper.