You do great work! I think a lot of people may appreciate character animations over character parts. You've got a lot here to make a game. I look forward to making a little something with it :-)
With the coins sprite sheets its easier to import things if they are the same width. So even when the coin is rotating and its with goes from 128 x 128 to 64 x 128 the sprite should still be 128 x 128.