I agree that what you just wrote is utterly senseless and incoherent. But that is not what I said. A contract is an INFORMATION right. A contract is not the scribblings on a piece of paper, but the information content of that contract is enforcible by the use of physical force. Similarly IP is an information right. So they have something in common. The argument "I can do whatever I want with my PHYSICAL property as long as I don't infringe your PHYSICAL property" is what most libertarians use against IP laws, but the same argument can be used against contracts. In both cases you are refusing to acknowledge that information may be the legitimate source of physical force.
Again, this is a non-sequitur. A contract is an agreement between individuals, a meeting of the minds, as it were.
Who cares? It's just information and I can do whatever I want with MY body so long as I physically don't harm you. Why isn't that a valid argument?
Because you're making a false equivalence. It wasn't until 1989 that copyright was even implicit in the United States. That came with the ratification of the Berne Convention.
IP laws are not inalienable rights, and they have been very significantly tightened, due to heavy industry lobbying, in the United States over the last 30 years, especially with several acts passed in the 90s. We had perfectly functioning contract law before significant copyright and other IP protections. The two are not inextricably linked.