Ok, I will work on the font tonight, hopefully have it done by the end of the weekend.
One quick question. Do all the letters need to be six pixels wide? Normally, the 8bit fonts (atari 400/800, c64, Apple][ and so on) had a varied width and set height (as seen here here). To keep the font readable, it would be best if we could use varied font width. It all depends on how are you coding it. I can provide you with a table of widths for each symbol, so they can be rendered with correct spacing.
If you are using a ttf or otf I can just do the spacing in the font file.
As for the other things. I think making your own (or at least tweaking the DB16) would make the games/system more recognizable.
As for scaling the window. I would love either a key combo or a parameter to run the program at 200 or 300% size of what it normally runs. Tweaking the window size by hand each time you run TIC is a little fiddly.
I will respond to the rest of your post later, it was a busy day for me and I want to get cracking on the font.