I think Corel Painter would be a good addition to the graphics side of things. I've been using it instead of photoshop for years and at least for me it's much nicer to work with when it comes to actual drawing/ painting. Photoshop is still much better for any sort of photo emitting of course.
I tried to use MagicaVoxel you already have on the list, just to try out the voxel thing. It seemed like a pretty good tool, but damn it, the whole menu layout is unintuitive as hell.