It's a thought provoking post.

One refinement is that there are a number of earlier challenges you faced that are now "solved problems" so some of the squares should be marked blue instead of black or white because it's a risk you have encountered and mastered. For example, how to file taxes as a corporation. How to hire someone.

A second refinement: there are also decision rules you can follow that limit your exposure to entire categories of risk. For example: don't finance your startup using credit card debt.