I'm A-OK with folks editing the sprites for their own benefits u w o/ knock yourself out~
The method I use for resizing though unfortunately pretty much requires an old outdated program no one uses anymore /)- 3 -; but I can try to describe it and maybe you can find a way on another program. I use Paintshop pro 7and in it, when you go to to resize there's an option to do a "pixel resize" in it, which means it'll just resize based on pixels rather then try to resize with antialias, making the sprites fuzzy or blurry. Pixel resize does leave the images looking pretty jagged and distorted, but so much easier to work with when you're working in sprites.
I mentioned this method sometime ago previously too
here and you can kind of see an example what I mean about the differences in normal resizes and pixel resizes. Here's another example of it using one of the animal sprites I quickly made:
it still requires cleanup but not nearly as much as through normal resizing methods o 3 o/ and saves a ton of time with the work. It's just at this point I have well over 60+ unique animal sprites (more like 100+ if you count recolors too) and that's a ton of work . _ .; Over the years I've tried out various programs, but most of them don't have this pixel resize option. I believe Gimp has a similar feature called "scale image" and under "quality" you select none, which should give you similar results but-- mm don't quote me on that one. I don't typically use gimp and further testing needs to be done lol. The plus side though is if you can figure out how to do this, it makes editing almost anything much much easier.