I have had a glance at 0.92 and what you have done seems excellent.
But my wife is the family artist, and although she likes to think she is computer-savvy, the system is much too 'busy' for her.
You have tried to do everything for everyone in it, while her needs are much simpler. A pressure sensitive non-textured brush, with layers, fills and transparency settings and the ability to trace a bitmap will see her well on her way.
Many other packages have gone the way of excessive complexity. Corel Draw was fine around version 8, but has since gone overboard. Other packages that are bitmap based offer so many brushes that they bewilder.
So I suggest that you also launch some 'lite' versions, in which you merely conceal a large number of the tools and their options, making the working space much friendlier. Of course customisation can achieve this, but if a released version has just the 'essential' tools with instructions on how to reveal more, you might get a wider and more appreciative take-up. Your testing should be performed by artists, not by computer professionals!
Best wishes John