That's very good work. Your pencil art in particular is as good as most of the people I took art class with in college. And you get better shading dynamics (contrasts between light and dark is what I mean by that) than some people I've run across who are part time professionals pencil artists. You're not hesitant to used darker shades.

The Microsoft Paint stills are pretty decent as well, but that is a quite limited program, and its' limitations show. The car art is good (and I'll bet the guys like that... )

I didn't watch much of the MS Paint videos, because I'm on dial-up and it would take longer times to load a whole video than you took to make them. Sorry 'bout that.
Until now I didn't know one could use paint to make videos, so I learned something.

One paint program you might want to look up and try some day is the one named Dogwaffle. You will see by the galleries at their site that one can do some spectacular work with it, animations among them.

And one can learn it fairly quickly. Heck, I'm an old guy and I can even use it.

I don't know if they still have the free version that I got a few years ago, but it won't hurt to look. The Pro version doesn't cost that much, compared to some others, if you decided to get it.

Google for 'dogwaffle. paint program' or go to their home page at:
http://www.thebest3d.com/dogwaffle/

I also use SketchUp for drawing some stuff.

Anyhow, you do pretty good work and I suggest you keep it up.
But save some time to play that guitar.