Police have the legal authority to enforce the law once they become police officers. Similarly, publicly elected officials have the legal authority to create the law once they become publicly elected officials.
You're assuming that since you don't have the power to create laws and I don't have the power to create laws, then nobody else does either. The power to create laws is granted to people once they are publicly elected to office.
You can disagree with that all you want and say that you don't think it should be that way, but that's how it works, that's the way it is
The power to delegate rights is granted to publicly elected individuals by the people that elect them
You give your consent to be represented by a representative of the government by living in one of the districts owned by the government. Nothing is stopping you from moving outside said district and voluntarily removing yourself from representation. By choosing to live where you live, you are choosing to give your consent to be governed.
The owner would have the right to determine the use/nonuse of the subject property so long as it follows the law. For example, it's illegal to discriminate against people based on the color of their skin, so if you owned a public establishment, you would not be allowed to discriminate against a group of people based on things the law protects against (race, color, religion, etc.). That wouldn't make the public establishment any less your property
Sure, I would agree being able to do what you want with your own property so long as it follows the law is what makes owned property, property and not something else