@Night Ripper,
To say we "don't have HAVE to die", to me, seems to be an attempt on your part to say something like this, "If the initial conditions of the universe were different in such a way as not require humans to need oxygen to live, then we wouldn't die", but that is quite obvious I would say.
You seem to be desiring to take the argument back to the initial conditions as your basis for suggesting cause and effect does not exist.
While I'm saying that I am starting with the assumption that those conditions are there. Given those conditions, within the system or the box that we actual world exists, certain cause and effect relationships do actually exist.
Your argument sort of reminds me of this: Say there are two roads in front of me, Road 1 and Road 2.
I'm sitting there are the fork and considering to myself which way to go. Clearly, up to this point no effects exist. However, once I actually decide to go down either Road 1 or Road 2, I have now created certain effects....maybe I'll get hit by a car, maybe if I had taken the other road I would have found a twenty dollar bill on the ground, who knows.
You seem to want to the argument to remain at the fork, whereas I'm saying, we are on Road 1....and because we are on Road 1, certain effects became real and actual.
Because we are on Road 1, X HAS to cause Y.
I hope that made any sense...