Here are some replies...
1.) This website took 90 minutes to create from idea to publishing.
2.) Eric, Steve, Brant, and Peter are in no way affiliated with this except they are awesome and helped inspire it.
3.) An MVP can mean many things to many people. I think you should do the least amount of work in order to validate/invalidate the most assumptions. "Get out of the building", show people sketches, create site mockups with buttons that don't work and calculate the number of people who pressed them,etc. Here's an article from Venture Hacks.
http://venturehacks.com/articles/minimum-viable-product-exam...
4.) Interesting thought about NDAs. I think I would take the same route as VCs. Don't sign them because they may inadvertently affect other projects you're working on. I probably won't be able to offer assurance except not doing it - also like VCs.
5.) What do I provide. Depends on the project, I think smaller is better to validate assumptions with the least effort. This way, you don't waste time building something people don't want.