I think you may have missed my point. Ok, energy cannot be created or destroyed. Given.
If you're saying that time itself "simply exists," then you need to provide the data supporting that argument. Time "has always existed" doesn't work, because we've agreed that time is finite. Other than in quantum physics, where we seem to have things which happen without causes or prior to cause, I can find no empirical evidence to suggest that time exists simply because it is.
The "because I said so" reasoning may work with five-year-olds, but won't with me. I need evidence. "No known cause" is different from "no cause" on a fundamental level. If someone is asserting that time has NO CAUSE, then they would need to prove that using empirical evidence (quite impossible) or repeatable tests.
You said:
I, on the other hand, would draw the simple conclusion, based on logic and evidence that whatever the uncaused thing is in the universe, it is that which cannot be created nor destroyed.
I entirely agree. However, I, of course, am arguing that this 'uncaused thing' is deity. Ultimately, that is the goal of my argument.
I feel strongly that the logic of my position is clear. If A, then B. Not A, therefore C. It is quite simply impossible to prove that a thing has NO CAUSE. If we were able to eliminate all possible known natural causes, the best science could conclude is "we just don't know." That is a tenable position in science.
To say, however, "it wasn't caused; it just exists" appears to me to be indistinguishable from "magic," "miracle," "God," or "The Flying Spaghetti Monster." It remains an unproven, unprovable assertion.
As far as you saying that we must conclude that there is at least one uncaused (natural) thing, why? What is your logical argument for such a thing? What is the evidence supporting such an argument. I think we're focused on time itself, since every other thing is dependent upon that for its existence.
We've agreed that time is finite. Before time existed, it didn't; nothing did - indeed, nothing COULD. At some point, time 'began'. If you want to maintain the position that "well, time just started. Nothing caused it. It just happened," then I would respectfully suggest that you provide the evidence I've requested to back up that assertion.
Absent that evidence, my own conclusion is that time didn't "just start," but was caused.
Am I way off base, or am I making sense? (Deconverted Man's standard answer: "Yes.")