I don't really think I care too much. I need something to eat that is more important right now.

That all of said energy has always existed in one form or another and if you're eyeing the big bang, that event was the transformation of an unknown energy into what we observe today.

Primitive man looked at the sky and asked why and made up many tales to explain the nature of the world (as they knew it). We have progressed far from that time but because science doesn't know or has ever claimed absolute knowledge -- only the religious claim that -- I will put what I know in science. I'm not a physicist so can not argue with you regarding your interpretation of the conservation of energy, but I'm sure you have run into others that can.

The Universe has always been here.

Everything makes sense, except the non sequitur at the end, “which is god”.

I'd say "Hi, nice to meet you, guess I have no choice but to obey you" to such an established law.

To you I'd ask "Which God? So many conflicting ones to choose from.".

God will always be said to exist just beyond where known science stops...except knowledge of science keeps growing, and so the god adherents must keep moving their goalposts. Our scientific knowledge stops at the big bang, or nanoseconds after it, more rightly. It doesn't take long to discover, even in near modern times, where the goal posts used to be...for we did not always have the theory of the big bang. We may, one day, discover more about prior to the big bang...or at least discover theories that scientifically prove prior to big bang. So... Ta-da. Their argument rendered moot! (Root: which side is moving the goalposts, and who is gaining ground and who is losing? And, has it effectively always moved in that direction?).

Pure horse crap. The process of creation of the universe is theorized and there may even be many universes (the multi-verse) [space.com]

This sounds like the watch maker hypothesis. Someone must have created watches as they cannot create themselves. So that means the watchmaker created itself. I don't think so. Remember, all these 'god' theories seem to have human at the center. It's called a conflict of interest.

Maybe, maybe not, but even if creationists etc. overturn every scientific theory ever made, that does not provide any proof of god, it only says that we need a new theory of which god will only be one of thousands.

Go big or go home is my advice. Point out how the universe has been measured to be flat and is quite possibly uniformly flat on large scales. If this is the case, (honestly we don't know yet but the evidence is favorable) then the net energy of the universe is zero, implying that the law of conservation of energy would not be violated, and all the positive mass/energy in the universe equals the amount of negative energy. Think of it like taking out a 0% interest loan from the bank. If you have $0 you can do nothing. if you have $1,000 and -$1,000 debt you can buy $1,000 of stuff.

Ummmm, there may very well be "something" , a force, a ray, a particle, etc.that we have not yet postulated a theory about.
But how do you, or anyone, immediately leap to the ASSumption it would be some kind of gawd?

Nature always was, which means that things evolved and were not created.

Simple. Ok, you are standing by a law of science so stand by it: how did god get energy? And keep a science answer, no bullshit he always had it Crap without proof.