Self-ownership

I've been thinking about some issues in libertarian thought today and I'm finding myself particularly confused about the notion of self-ownership that underlies (most?) libertarianism. For more on that notion, see Libertarianism at the Stanford Encyclopedia of Philosophy.

There seem to be at least two important issues with this notion: 

First, there's something decidedly odd in taking the ground of our morality from the relationship that we have to things we own, because whatever sense we might be able to make out of owning ourselves, our primary notion of ownership is our ownership of external objects. The idea that we own ourselves is taken by analogy from that epistemologically primary notion of ownership. 

Second, ownership looks like a two place relationship, one that must take two different things for its arguments. That is, ownership appears, at least in the normal case to be Oxy, where x≠y and Oxy>¬Oyx. This, at any rate, is the way the notion operates in the normal case; to allow self-ownership seems to be introducing a new notion that will be called "ownership" but that has little or nothing to do with ownership.