The foundation, or "proof" as you call it, of God's existence was not determined by a Catholic propagandist from the 1200's. Today's grade-school children have greater discernment and better sense than this man. To have been venerated by the Catholic church, he would have had to promote that the Pope was the living manifestation of God on Earth and whatever other fundamentalist nonsense was dictated by his indoctrination into theological "philosophy". He would have viewed free thinkers as heathens and anything opposing the Cathollic concept of God as heresy.
But let's address his insane ramblings:
1. The "argument from motion" is a paradox. It is full of sentiment, assumption and speculation. Just as easily as we can speculate that there must be a "first mover" and assign a human personality to it, we can also speculate that "the singularity" was not the first event to have ever occurred in all of reality. Also, if a "first mover" was to exist as was assumed in the "proof", the implication is that the "first mover" began all things and is outside all time and space, eternal. If not time and space, then something must extend infinitely in all directions through all dimensions or some lack thereof, and this is assumed to be the "first mover". Either without time and space, or if time and space were infinite, both of which are impossible, it would be irrational to think that any instance could occur. By this rationale, we don't exist, and neither does the "first mover".
2. First Cause. He argues against himself again here, determining that the "first mover" can't have existed eternally because nothing can exist prior to itself, and nothing exists which hasn't been initiated by something else. To paraphrase this nonsense, he says "I'm confused, therefore God". It's ridiculous to use examples from observable reality to support claims of imaginary things that not only have no foundation in observable reality but effectively contradict it.
3. Necessary Being. Here he hits the nail on the head by iterating what I just pointed out in my previous rant: that this is all absurd. Again, a paradox. "I'm confused, therefore God".
4. Degree. To assume any intrinsic valuation is preposterous. He is now preaching based on abstractions such as nobility and truth that a God, who if human would be a raging sociopath, is responsible for all that is good and decent in humans but not responsible for anything that is corrupt or evil.
5. He presumes, again based on religious belief and in the absence of science, that anything that doesn't appear to be self-aware by human standards is unintelligent and aimless, which was fine in the 1200's, when everyone was a blithering moron, but none of this stuff holds true in modern times.
This argument, and it's no argument at all, is just another confused rant from a place of scientific ignorance and intellectual deficiency. If its writer isn't intellectually deficient, then he's attempting to mislead his reader and pander to authorities his life depends on. The only thing infinite here is the writer's self-contradiction.