It turns out I did some more work on the test_shiplib after I uploaded it. I don't have a place to upload it though, because I used all the webspace on my account...
You could do something like what you're saying with the source, as long as you didn't want too advanced of a GUI. You could read the type of data and field names (string, number, fraction) from the source, but not much else beyond that.
It really wouldn't be worth the effort, IMHO. It wouldn't be possible to do it with just the executable either.
BUT I did something somewhat like that, in that I linked to the fs2_open code with my program so if a data structure is updated in the source, it'll be updated whenever the program is rebuilt as well. The program still has to be updated by hand when new fields are added, but only to convert them to the right format and to have a place to show them.
Apologies if that's confusing, it's an odd mix of coding terms and not-quite-layman's terms.