Capitalism, Communism, Socialiasm, and Collectivism all have property rights. They are structured somewhat differently, but they all recognize that some things can be owned, and some cannot.
You can't build a consistent legal, or ethical system from the first principle of "Property rights are the most important right."
Yes; but rather that they aren't more important than people. Well, that is actually silly because under the right circumstances, it could be that the property (or any other) rights of person A are more important than all of person B as such. It's just trivially true when A = B (A and B are the same person). No right attributed to A is more important than A him or herself.
You can't build a consistent legal, or ethical system from the first principle of "Property rights are the most important right."