cartographic conundrums

I've run into a bit of a puzzle with my game and was wondering anyone else has had the same problem or had some advice.

When working on your world map, what sort of scale should you use? Do you make one large map in with transfers to the individual villages and dungeons? This seems like it would give you that wide-open, epic feel, and would make ship/airship travel more realistic. On foot, however, it seems like a lot of wandering, and would be tricky to manage when making the map.

Or do you have a map, say, for each kingdom with transfers linking the kingdoms in addition to the villages and dungeons? This would break things up into easy-to-digest chunks, but it seems like you would loose that sense of scale. Plus, how would one utilize airships, etc in this sort of setup?

And while we're on it, how many villages and things should one populate their world with? I've played games where the sparsity of towns seemed unrealistic and made the world seem small and ill-planned. On the other hand, towns and things need to have a reason beyond verisimilitude, don't they? Some feature which makes you want to go there.

Bump?

A game called Casia had a map where you had to walk everywhere, but if you took a ship, you got the worldmap view.

Does your game need airships?

I personally prefer the worldmap view when walking around.

Well, I'm not sure about the airship. I think something like that can open up opportunities for exploring secret areas you can't get to by foot. I thought about creating a separate world map for vehicle travel, with individual "region" maps for foot travel. (Eg: map1: kingdom of terra; map2: ignis island, etc.)

but there's still the issue of how many villages and towns should populate your world and how near they should be to each other.

Hmm, what if instead of the world it is just one country? That way you don't have to worry about the amount of villages seeming spare.

Well, that would make a difference. A game taking place within a single kingdom or region (as in the pokemon games) definitely simplifies the scale issue. But what about those cases which dictate the use of multiple nations?

Is there some rule of thumb regarding the frequency of towns when the story requires you to cross the border?