[CdM] Libertarian, definitely. And there is a libertarian answer to the question of how things could work without governments, for which see David Friedman's book
The Machinery of Freedom (which I haven't read, but I have read a lot of his postings to Usenet). He has
a web site with related essays and sample chapters from the book.
The problem with the social contract idea is that it isn't a contract in any reasonable sense of the word. I don't have a choice about it (beyond emigrating to live under someone else's social contract) and its terms are nowhere defined. In practice, they are defined as obligating people and governments to do exactly what the person invoking it thinks they ought to do. It's as empty as religionists explaining how the elephant got its nose by saying God made it that way.
[Projoy] I don't see there (in the "Compassionate Conservatism and Tax Cuts" section) any argument that these things must be done by governments, only the unsupported assertion accompanied by (to borrow an epithet he uses a few sentences later) a simplistic caricature of the idea. So where he says that "it's our money" is a simplistic and indefensible way to think about tax, I would say it's a simplistic and defensible way to think about tax.
Something that might be worth reading alongside Singer's utilitarian writings is C. S. Lewis'
The Abolition Of Man.