Unbridled Utilitarianism, taken to the extreme, would mandate some form of forced Socialism.

So maybe some form of forced socialism is right. But you don't seem interested in considering that possibility. Why not?

While Utilitarianism is excellent for considering consequences, I think it's a mistake to try and raise it as a moral principle.

Why not?

It seems like you have some pre-established moral principles which you are using in your arguments against utilitarianism. Right?

I don't see how you can compromise on these principles. Either each person has full ownership of themselves (so long as they don't infringe on others), or they have zero ownership.

To me it seems that most people making difficult moral decisions make complicated compromises between competing principles.