These rules are nothing new. Every company seems to start this way and then eventually each of these principles die with a little regulation here and a little adjustment there.
It's possible to keep improving in this area, but you need a strong culture to support it, and inspiration from companies that show you that it can be done. In our case, the Valve handbook was enormously motivating: if a 300+ person company can operate with so few rules, what is our 50 person company really complaining about?
Policies that can be changed willy-nilly by some higher-up are really just meaningless platitudes (redundancy for emphasis).
To clarify, not every policy and procedure (of which there are precious few) are in there, just the big ones that that shouldn't change without everyone agreeing (results only work environment, unlimited vacation/sick, profit sharing, etc.).
Departmental ones, like "test coverage should be > n%" or "we should answer every customer service request in under n-minutes" are totally up to each group to manage as they see fit.