Most of this is just bluster and argument from authority. The only substantive critique I see you making here is that pg's suggestion about decoupling wealth and power won't work because wealth is power. But your definition of "power" is "increased ability to do something", whereas pg's implicit definition of "power" was "the ability to corrupt important social processes that are supposed to treat everyone fairly".

So I don't see the force of your critique: pg and you can both be right. Wealthy people can have more ability to do things even if there are systems in place to prevent them from corrupting particular processes that are considered worthy of such protection.