Sorry, I couldn't resist.

"Time is just a dimension. Height, width, length and time. The four dimensions."
"The problem is that if you go backwards to the big bang there is a point where 4d space-time did not exist..."
"...how did a universe that did not have space-time (as we understand it) create a universe that does?"

An assumption I think you are making (and that I fundamentally disagree with) is that time is limited. If that is so, are the other dimensions also limited? If it is not so, when did the universe (and time) start to exist? I believe the universe is infinite in time as well as the other dimensions.