@bryface, I am also questing for a keyboard driven pixel art editor.
Did you get grafx2 to work this way? I'm going to try that. I adore grafx2 but don't use it as much as other offerings that are easier to futz with these days.
One thing I was considering, ANY program can be keyboard driven with the accessibility options in windows called Mousekeys? I think you can move the cursor by individual pixels, and then there is left click and right click keys you can use too. This would allow any existing software to do it. Granted it's not going to be like our old trust ANSI editors
That said, I did find something kind of in-between called teletext, and here is an editor for windows:
http://teastop.co.uk/teletext/wxted/
I'm quite fond of this editor. It lets you plot teletext using keyboard, just like our ANSI - the reason I mention is because while we don't have access to the full pixel palette of colors, the minimalism will force creativity.
I share this example screenshot:
(and yes before you ask, that's a sloth )
Also you probably already know this, but PabloDraw is an excellent windows ANSI editor that will let you use any colors you want, if you save in XBin mode.
http://picoe.ca/products/pablodraw
Text Formats: ANSI, ANSI/24, ASCII, ADF, Avatar, BIN, CG, IDF, Tundra, CtrlA, XBIN, Animated ANSI
Vector Formats: RIPscrip
Also not to spam the entire thread, but this is an example of me using pablo recently (as well as some modern techniques) perhaps you might enjoy this:
https://www.youtube.com/watch?v=lNEjb-dbvqg