The append function only works if you are appending from native .blend files. Sadly, .obj doesnt import or export armature information. I use the .x format for exporting armature data to my game, but im not sure if Blender will recreate the actual bone structure for you or not when importing. I will test this :)

I have finished parts 1 and 2 of a tutorial for using Blender to unwrap a full character model, touching on a few more basics than just projecting a plane. I am hoping it will be approved soon.

Shape keys are generally used for facial animation.