Merri: Yeah, you'll need to finish the map on your own. The main purpose of the map generator is to make it much easier to do maps: most often you spent an awful lot of time making a landmass. For some reason a lot of people end up with very dull maps, like flat grass only... so this is where map generator makes life easier. Just generate a landmass you like and then start working on it.
The generator could do more, but as I've probably said before, that depends entirely on whether I have the interest vs. time to do it. Anyway, some improvements could include a better support for GOG version of the game, such as autodetection of the correct folders.