I can answer some of your other questions.
1. Read my post above. Mark has a peanut shell for his child.
2. You'll need Kryptonite's largest u-lock (the long shackle kind). To make it more convenient, buy a chain from Albus (or another Euro company) or Kryptonite.
3. Yes.
See this photo. My Mundo (in progress) will have Fat Frank tires.
4. The seat pad does not interfere.
See this photo.
5. I don't know
