The GIMP image editor is not nearly as challenging as you might think. There are several things you can do to improve your workflow. All of these tips are free to use. I've been using the GIMP image ...

I don't think you can. I'm assuming you mean 16-bit per color, or 48-bpp, right? I'm pretty sure that the Gimp's internal color precision is only 24-bit, so it's probably dithering down to that when ...