You can't contemplate if you are dead---someone could kill you and you would lose this ability therefore it is not inalienable.
Nonsense. By your non sequitur there are no rights, there is no life, and nothing exists at all because all living things have a beginning and an end. Thus by your argument a thing can't exist between the beginning and end if it can't exist outside the timeline between the beginning and end.
Then let's just go ahead and call everything man does a natural right and call it a day. I mean what good are they anyway ?
Good point, and a much better question.
The point is only certain of our rights should be legislated by the federal government, that is what good they are. They are good to show and/or elevate differences between that which should be regulated and that which should not be regulated by said potentially tyrannical forces.
Look what happens when we are not paying attention. Look at the 14th amendment where the government gave itself the power to take your life, liberty, and property by due process, wherein the due process is what they say is due process. Look at the un-patriot act. We are but slaves to a government, that has declared itself our judge, jury, and conviction-er.