I think I agree with everything but #1. Completely shutting off from people who although may not invest, can still provide valuable information or advice as they may have experienced something you have not.
Personally, I get the feeling that most people who start a company are tired of _some_ status quo, and have strong opinions on how they want the end product to look like. Therefore, the last thing they want to do is listen to people telling them how their product should be. And since initially, all you care about are the technical challenges, it stands to reason that coding minutes and hours are more useful than schmoozing and advice garnering.