I just checked the paid links on Google's search page. They do not use nofollow. This fact, combined with your arguments, is consistent with gojomo's hypothesis about Google wanting to monopolize paid links.
And similarly: "We crawl your stuff; but our search results are off-limits." Of course, anyone can block Google, but given the asymmetry in business models and market power that's not much of an equalizing factor.
I like Google and think they mean well. Individually each of these policies has a reasonable basis. But Google is now so dominant -- and the positive financial rewards they get from self-serving policies so large -- that their actions deserve close scrutiny.
(The Freud-inspired quote I led with was originally about the state; Google's influence on the net is so large that they are a lot like the net's government.)