First, thanks for a great app! I use it every day. Quite happy for it!
Something that would save me (and others?) a bit of time has to do with layer names. When I open an image file, Paint.net names it "background" in the layers window. two issues with this.
1) Typically, the png image I open has no background. So each time I plan to work with several layers, I either need to think of something creative to call my actual background layer, or rename the layer with the original png image. Not a super hassle, but a nuisance. Go ahead, call me picky.
2) (and more of an actual problem) I often work on more than one image at once. Each might have several layers. If the original image were identified by its file name, I could more easily tell at a glance which image/layer I was working on as I ctrl+tab my way from one image to another.
Cheers,
David