Great article Alex Chuang, thanks for sharing.
When it comes to point 7 I’d say that special attention should be given to the time box of the expected metrics. It is very easy to “just wait a little longer” and forget that you were meant to hit 50 sign ups in seven days, not 14 or 29 days.
The toughest bit in learning through the scientific method is that you have to be honest with yourself… Even if it hurts. :)