1.
I've decided to use 3D printing because it brings the possibility of transforming your ideas and digital creations into a physical object closer to the masses at an affordable price. For example, a lot of people can draw and make 3D models of their ideas in today's world. If there weren't 3D printing services around, if you wanted a physical representation of your idea, you'd have to contact somebody who can do it using other means. Most of the time it's expensive because you'll be hiring professionals who specialize in that sort of thing (like pro prop and special effects makers or actual sculptors). With 3D printing, as long as you have the correct file format of your idea represented as a 3D object, it's possible to have it made quickly even in full color. Since the technology is new (at least for public use), there are still limitations but I'm pretty sure that progress will be made and there will be more freedom when it comes to "printing" 3D objects. I hope that someday, we'll be able to print in any material with color with as high detail as possible without breaking easily.
As for what I make, I specialize in original fantasy figures and accessories as well as writing stories for them.
2.
I create and only sell my own designs to the public. I want to establish my own brand that people would love and enjoy. I respect the people who own rights to popular things like Mario, Batman, and others. I know that those things might sell a lot faster, but for sure I don't want anyone stealing my ideas and selling it as their own without giving me a share of the money. Besides, that is illegal.
3.
I am the designer, 3D modeler, and writer of my shop called Dragon's Desire, which you can visit here ->
https://www.shapeways.com/shops/dragonsdesire 
I hope my answers help you with your project!