Creation Revisited

These days I spend a lot of time in discussion with friends and foes who are theists. The vast majority are Christians, likely because I live in Kansas and religious diversity here means you're either Pentecostal or Baptist. I also thrive on websites like AnswersInGenesis that I have mentioned before. Many arguments for a young earth or for creation are pretty obviously based on poor assumptions or bad science, but those are not what I would like to talk about today.
I am not a scientist by any stretch of the imagination. At best I have a very basic understanding of how science works. To put this in perspective, I have a basic understanding of how my car works. I can do simple repairs and even diagnose some issues that come up. Ask me to build you a car and I would do well just to draw a picture of one. However, I don't need to know all there is to know about the design and production of a vehicle in order to hold an informed opinion on it. The same is true of science and the origins of the universe.
However, I am much more comfortable approaching the subject of Creation from a philosophical standpoint. So hang in there, because I'm not sure any of this will make sense.
Something cannot come from nothing: Creationists claim the universe must have had a creator because it could not have come into being without one. Now, we know the universe exists, mainly becuase we're here to experience it, anthropic principal and all. The best science we have can't tell us with certainty how the universe began, or honestly that it "began" at all. What came before the Big Bang is a mystery and one that an honest person has no evidence to fill in.
The universe also apprears to be rather complex. Alright...mind-bendingly complex. Like, way more complex than I can really wrap my head around. I think we can all agree on that. Except for that Hawking asshole. I swear if he wasn't in a wheelchair, I'd kick his ass for being so smart. Then again....he might be able to kill me with his mind.
Sorry. Anyway, so this vast, impossibly complex and spectacular universe exists and nobody can honestly say how or why. Creationists will say that God simply willed everything into being. Even if I am willing to allow that (and in no way am I willing to do so), how does that make more sense? God, by definition, must be even more complex than the universe in order to create it. And he must exist on some level in order to be present before anything else was so that he could create.
My point is this: Why does it seem so easy for creationists to postulate an all-powerful creator who doesn't need a reason for his existence over a natural, but as-yet-unknown reason for the universe's existence?
We know, without doubt, that the universe exists. So however unlikey it might be, here we are, existing in it. We do not know that God exists. (Even the strongest believer admits that faith is not knowledge). To me, taking that extra step seems unnecessary and unwarranted.