Wow these presets look great. I love seeing how much of an improvement you've made, especially with the specific ones like the glow and moving one. Do you plan on making more because I definitely would love to see more.
I started out with Gimp and I still use Paint.Net but only for putting it together (like adding layers and stuff)
I think you should definitely try out Paint Tool Sai. I use it now and I have to say it's my favorite program so far. You'll have a blast messing around.