It's all quite possible, and why I made them the way I did.  The upper is all a single plane suitable for tranmapped textures, the sole/last part can be made thicker or thinner quite easily, though you wouldn't want to go TOO far either way or the texture would get mangled.  Changing the heel height is tricker as it will require bending the whole business and I'm a point pusher like ODF, but it's possible, yes.  Probably easiest (for me) to make it into a figure in D|S and bend it that way and export as an obj then fix the heel to match in hex.