I am an orthodox Christian, ask me a question!

[Jon Paul]

I've been through this and you've posted this enough times - this is not evidence! And scripture irrelevant here - arguing from scripture is fallacious - it's circular reasoning.

It's irrelevant that you have seen the post. You haven't refuted it's contents. And no, it's not circular reasoning, the Summa Theologica is not scripture, and even when it has references to scriptures, it gives natural arguments.

You claim that if an atemporal being (actus purus) was temporal and arose from chance alone, this [being] would be complex.

so I'm not talking about an atemporal God being temporal, that would obviously be a self-contradiction and I'm obviously not claiming that!!

You are exactly not talking about that, and I didn't say you were.

I'm saying that if he wasn't atemporal/nontemporal (Got that?! IF) then he would be complex....

And that's what I addressed. You cannot speak of a hypothetical scenario in which the ontology of God wasn't nontemporal - because then you are not addressing the ontology of God, but the ontology of something else which isn't actus purus. The ontology of God necessitates nontemporality (e.g. actus purus is not a potentiality which is actualised/an entity that "arises", but pure actuality and not a potentiality and with nothing of potentiality), and if nontemporality is not the case, it means actus purus it not the case, and in such an if-scenario, we are no longer speaking of God. This is the part about divine simplicity you haven't understood - all of Gods attributes are equal to and necessitated by Gods being, and not arbitrarily predicated. You cannot take one away, therefore. It's all or none.

As I have said: 1. If he was temporal and arose from chance alone this would be complex (..)

You claim that if an atemporal being (actus purus) was temporal and arose from chance alone, this [being] would be complex. I reply: no, it is a self-contradiction, it cannot be even in theory nevermind in praxis, because it contains a contradiction in terms. The only way you can claim that it is possible either in theory or practice to consider the scenario that "if God was temporal and arised from chance alone", is to address a God who is not actus purus, because actus purus necessitates nontemporality (e.g. God is not a potentiality which is actualised/an entity that "arises"). If you do that, then you are addressing a temporal ontology which is not actus purus, and thereby not God, and this equals to the straw man or non-sequitur of pretending to make significantive conclusions about the status of actus purus complexity by addressing the status of complexity of something which is not actus purus. Since it is not actus purus, it would have none of the other attributes of God, either; such as omnipotence, omnipresence, eternality, omniscience, etc, since all of these attributes are ultimately equal to actus purus, and are not arbitrarily predicated, and do not exist without actus purus. In other words, God cannot be temporal and "arise by chance", and still be God. A random object with a spatiotemporal and material ontology can.

I can also ask, "if a green apple was not an apple, but an orange, then this or that". But then I am no longer addressing an apple, nevermind a green one. It happens so that the apple has the accident of being green (you could find a red one which is still an apple), while God is void of accidents and has no non-essential qualities, for he is his essence, which is purely actuality.