In case you didn't notice, I was asking the same question as you.
And yes, of *course* you can "paint" without a mouse. For example: a stylus, a touch screen or even cursor keys. You can create an entire image with The Gimp and a script-foo file without displaying a single pixel. You can convert, resize, crop or filter with a command-line ImageMagick script. Et cetera, ad infinitum
As Leopard and I asked, your question seems to be:
Is there a graphical program (a paint program) that works without graphics (in text mode)?
I *think* you're asking a legitimate question. But we don't quite understand - we're missing something.
What exactly are you trying to do? What is the "context"?
Thanx in advance .. PSM