It is not possible to prove a negative.
Not true. You are confusing a debate rule with logic.
You prove a negative by proving that something incompatible is posititive. For example, you can prove -- with your birthdate -- that you did not shoot Abraham Lincoln. See next comment for how this applies to rights.
You must use a standard of permissable actions to decide what is allowable, or rather, what can be defined as a right.
No -- in a free society -- the limitation is a standard of permissible areas for state restrictions. Everything else is a right by default. The state must prove that the action is something is within its legitimate powers to restrict. With that proof, it has proven the negative: the action is not a right.
Privacy is not an action and just because an act is performed in private does not mean that the act itself is protected.
No, privacy is actually a state of being. States of being are protected by the Constitution; for example: "The right of the People to be secure in their persons, houses, papers and effects against unreasonable searches and seizures..." (Amendment III).
Re:
"just because an act is performed in private": To break the veil of privacy to stop an act, the state must show that the prohibited act (say murder or rape) rises to the level that triggers use of its legitimate powers.
However, you do not have the "right" to be given that state of being. You have the right to wellbeing, but the government (or others) do no owe you wellbeing. Welfare is wrong because it makes this mistake. The difference is that between "not taking away" and "giving."
But, one can argue that certain behaviors are detrimental to society and therefore should be prohibited.
Prove that consensual sex hurts society to a degree that legitmizes state power to break the veil of privacy and stop it.
"All rights"???? Huh? What do you define as "all rights"? Is your list a personal one based on your own philosophy or a legal one?
It is based on the 9th Amendment's assertion that there are rights beyond those enumerated.
I recognize that society has a claim to debating whether XYZ is a right -- I just allign with the side that says the burden of proof is on the state.
Perhaps getting a hummer hurts society to a degree that the state must break the veil of privacy to stop it. Prove it.
Technically, RvW depends on the definition of "person". Currently, a fetus does not meet this definition.
Yes. Thus, whether you think it is a person will govern whether you think it has rights that trump the mother's right to medical privacy. Sometimes rights trump other rights. You have the right to gather wealth, but another's right to life means you can't exercise that right by killing another to take his money.