"You haven't seen everything, so you can't know if causality is constant."<quoted text>
The first cause argument is not applicable to the universe as an entity. The idea of causality is derived from experience with objects much smaller than universes that are contained in them. You cannot extend the inductions (generalizations) derived from studying the whole and apply them to the parts. That one is called a fallacy of composition. From http://en.wikipedia.org/wiki/Fallacy_of_compo... :
"The fallacy of composition arises when one infers that something is true of the whole from the fact that it is true of some part of the whole. For example: "This fragment of metal cannot be fractured with a hammer, therefore the machine of which it is a part cannot be fractured with a hammer."
We don't have enough information about universes to generalize about them, and there is an excellent argument against anything existing before time. Causes imply a before state and an after state. The word "before" has no meaning until T = 0+.
There is no "before time" just as there is nothing on earth south of the South Pole. The phrase is meaningless, as is the claim of a first cause preceding time.
Nice attempt at a rescuing device.
Interesting how you personally however can claim the opposite:
"I haven't seen everything but I do know that causality is not constant."
Interesting that, don't you think?
But you can.
An appeal to your own omniscience perhaps?