P3 has the same flaw as Zeno's paradoxes, where there is a false assumption that the sum of infinite things must itself be infinite. If this were true, calculus class would be much easier, as all of those infinite sums would have the same answer. Since we know that the sum of an infinity achieved by infinite division of a finite is a finite itself, we are unable to tell whether it would take infinite or finite power to move these infinite things.
P1 fails to account for the possibility of multiple gods or gods other than the one this proof is presumably about. No evidence is provided for the claims of incorporeality or infinite power, either, without which the proof could well be proving that something more powerful than god exists, but not necessarily that god does.
The entire proof, flaws aside, only endeavors to prove that something god-like once existed, but not that it still exists or has any relation to what people historically have called god.