I don't think you are wrong in your overall point. My post was an analysis of the social evolution of self-expression. That was its direction. Your points relate to the actual utility of having no identity. The merits of your points (while anonymous) exist, but I would argue that they could not exist if not for the experiences derived under a rigid identity, perhaps not even without the experiences derived from having an identity on the web anywhere. How do you know that you care about identity or UPP or not if you did not experience both the "have" and "have not" have not at some point? Your opinion comes out of the in-between, and knowing both ways.
Edit: upvote for your throwaway, new account to prove your point. I imagine it would not have preceded a real account that you care about.