So, back on track with the main topic.
I took a look at lua(c)-wow, and the listing output seems pretty straightforward. I'm not sure exactly what
all the columns mean, but I think I understand enough of them to make something like that work.
Just have to dig around in the source to find out how to redirect the listing output, and then I should be able to compile it as a lib, and use it within the application.
So...first feature suggestion is simply a UI thing. Giving an option for a global folder name ignore, and a local one on open, is really the only thing necessary - beyond using those items in the search.
Second feature is also mostly a UI thing, though it does require loading up the file, and digging out the line. Nothing a simple split can't fix.
Third thing - well, getting an error isn't a problem; but not sure about that "unknown error" thing. You might have to find a file that generates that error, and pass it on to me. For all I know it could actually just be a bug in the application itself.