but rather that the societies should be built around the systems and aim to enforce a certain way of life. The way I understand it, we mean the exact opposite of what you're saying.

That makes no sense. Who is going to decide which system to build a society around of? And since people will not have reached a consensus on the system they wish, how are you going to make them start building it?

Second, no the utilitarian solution is a normative one. It does not have to ultimately depend on what we have now available. For example a utilitarian perspective leads me to renounce private property in favour of possession.

Nor will a new system be based on the influence of those who own more. I do not see how this can be, as those who own more now, obviously will wish to retain it as it is

That being said, as an individualist, I must absolutely disagree that the only alternative is a cold, crass utilitarian calculation. Furthermore, such utilitarian processes are self-defeating because they will inevitably depend on the ownership system already in place: people who have more influence (in general, the people who own more) will have the most say in the new ownership system, and thus they will only seek to further their class interests.

When we say ownership systems are anchored by social consensus, we do not mean that social consensus should create those systems, but rather that the societies should be built around the systems and aim to enforce a certain way of life. The way I understand it, we mean the exact opposite of what you're saying.