I think all three of these principles are important but miss an obvious one that should come first. A decentralized web should have decentralization as its central principle.

If we're talking about our ideal pie-in-the-sky protocol (where people have total control over their data) then let's dream big. Web hosting should be completely decentralized. DDOS attacks should become infeasible because there are no dedicated servers to target and web services should already scale directly in proportion to usage. Entities should receive incentives for participating in the protocol, but have no feasible way of negatively affecting others no matter how much relative computing power they control in the network.