Interesting. I take it that you can type on a keyboard and handle a mouse.
Makehuman alone won't do everything you are trying to do; you will need a full design/animation program like Blender.
Without prying, are you able to use a gamepad? That would help immensely in your design work, if you can't do fine detail work like drawing.
I'm assuming that you are working on a Windows machine, or on a new Mac. They should have interface devices to help you.
