Another question is, who created God? What was before God? Was it nothing? Well, there can't be nothing, there had to be something? Who created the space which God dwells in before God was created? Dwelling on these question will drive you insane.
I was just arguing in the terms of what was already said, lawyer style. Oy, but just because the universe is the realm in which cause and effect apply doesn't means it's cause or effect itself. What cause or effect would you apply to the universe anyway? I mean, yes, there's the 'God said "SHIZAM!" (cause), and all of creation came to be (effect)' one. Even then you would have to ask for the cause of God, as his existence must be the effect of something if cause and effect apply to everything (unless he's the effect of cause and effect, that would be cool). And you went into tha in the end of your post anyway, my bad. With infinity in mind, I've been thinking about the concept of scale. No matter how well we can see things, down to the atom, there's always something smaller that makes it up, and vice-versa for larger. Both sides of the realm affect the ways in which our lives work, from making plastics, to having a planet which can feature what we definte as life, due to it's positioning. Working on it. But like I said, it could just exist. Nothing needs to be created in order to be; everything always was and always will be in existence; the variation is the order by which things are.
There is something called the Plank Length, derived from 3 constants: the speed of light, Plank's constant, and the gravitational constant, that is thought to be the smallest length. It is 1.6x10^-35 meters, or 1/10^20 the diameter of a proton. So theoretically, there is a limit. So far I haven't seen any infinities except in math. But you're right, infinity is way out there... consider a number called googleplex (10 to the power of a google). It is so large, that there is not even room to write it out in the universe! Yet it is just as far from infinity as is the number one. As for the first cause paradox, there is no solution. We must accept that it somehow works differently than that.