In the first animation, how about also making his arms move a bit, in stead of just his legs? In the second animation, the character just "slides" forward magically without making any steps. Was that the effect you wanted? If not, you might  want to consider adding a few steps to it.

Sure, if it's generic art that won't be used in a game, then by all means, use any size you like.

But for games, still to this day, textures that are power-of-two sizes are required or at least a lot faster to use than arbitrary sized bitmaps. OpenGL, for instance, used to require power of two sized textures, although arbitrary size extensions exist, they are usually slower than power of two because they automatically convert the texture to power of two sizes. And for certain subsets of OpenGL, like the ones used on those "toenail" sized devices devices, power of two sizes are still needed. Because of the way our binary computers work, power of two sized bitmaps will always be faster to use in games than other sizes. Sorry to be pedantic about this, but I'm a game programmer, I researched this, and that's the way it is.

For the Buster Sword, sure the handle needs to be offset a bit, but to the other side. On the cutting edge, the sword is much thinner, and hence, much lighter than on the backbone side. The Buster's hanle should be towards the backside of the blade, just like how, for example on a katana, the handle is "curved" in the direction of the backside of the blade.

Nice effort! You guys should keep practicing pixel art.