I would like to continue using Painter but...

[handrawn]

Re issue 5 of your original post:

Firstly, if you are using 'Digital Watercolor' which works on a normal layer, you need to go to layer menu and select 'dry digital watercolor' - once you have done this, color corrections can be made

Secondly if you are using 'Watercolor' - this works on a special layer, and to make color correction you will need to commit the work done on that layer to 'image' before you can color correct - you should get a dialog box as attached [unless you have supressed it, when commit will happed automatically] - committing will dry the color too, so there is no need to do that seperately in this case