I've always regarded the arguments that Luke cites against Dawkins' central argument as being awfully weak.

Yes, theists believe that God is eternal and necessary, a "non-contingent" being, as they say. But you could just as easily say that the universe itself is necessary and non-contingent. It doesn't seem to have existed in its current form forever, but that doesn't mean that the process which gave rise to the Big Bang ever had to be caused by anything, or could possibly have not existed.

Maybe the universe is necessary and non-contingent, maybe not. But the fact that it exists is established beyond reasonable doubt. We're not taking up a big unnecessary complexity burden by positing the existence of the universe. God, on the other hand, is a big complexity burden. You can say that he's non-contingent, that he couldn't possibly not exist, but you could say that about anything, and we don't have any actual evidence for that assertion.

When dealing with a causal chain, you're ultimately going to end up with an infinite regression or an uncaused cause. What Dawkins argues is that if you're going to posit an uncaused cause, God, as an intelligent being, is a far more complex explanation than a simple uncaused cause, such as some sort of basic physical principle.

Some believers will respond that God is simple, he has no moving parts and is ontologically basic. But of course, again, there's no end to the hypothetical entities you could posit and say that they're ontologically basic, but they can't even establish that intelligent ontologically basic entities is a coherent idea, and even if they could, it would leave the question of how we single out their conception of God as the specific ontologically basic causal agent to believe in. He has qualities attributed to him which you could not attribute to an ontologically basic causal entity, so as an explanatory hypothesis he can't be minimally complex.