Hey Eahoth!
Save as option: Right now I have to copy and paste in a new file to generate a new version of an .xp, pretty annoying!
Actually you're in luck, because REXPaint already has a feature equivalent to Save as
(I'd highly recommend you check out the manual, which lists and explains a
ton of features that you won't see in the program because they require hotkeys.)
To create a copy of the current image under a new name, you just have to switch to the image browser and Shift-click on the filename, which opens a dialogue asking you to name the new file (it will even suggest a name for you so you can just hit Enter to accept) and bam, you've got a complete copy to create a new variant or whatever you like!
The numeric keyboard doesn't work, and it's the first thing I try when entering some numbers, annoying OVER 9000.
By this I think you mean the numpad instead of the number row? I'll consider it for a future version, but the engine I'm using always treats the numpad keys as special use keys rather than numbers, which is why that's not a thing. I'd have to do some more low-level tweaking, and make sure it doesn't break anything else, before that's possible.
It would also be cool if you could drag and drop colors in the palette to generate copies (or copy the color values easily to paste in a new one), useful to get variations from a previous color. This one is not that annoying 
.[/li][/list]
Again, check out the manual. You can do this and a lot more in terms of palette manipulation--it doesn't support drag-drop, but you can click-copy colors for editing. (Drag drop would be even nicer, but it takes a lot longer to implement and test so is not an approach I decided to go with for now. I'll make note of it for the future UI upgrade though!)
