So you don't assume a first cause. Ok. one thing I am not seeing is actual evidence that determinism is correct, rather than things being probabilistic. There are many varieties of QM that are not deterministic. If everything is deterministic, there is no such thing as actual choice, because your 'choices' are preprogramed and predetermined.
An "actual" choice is the output of a choosing process. Choosing inputs two or more options, applies some criteria of comparative evaluation, and outputs a single choice. We can observe choosing actually happening in a restaurant. The customer walks in, sits at a table, browses the menu, and tells the waiter what they will have for dinner. The multiple options on the menu have been reduced, by selection, to a single dinner order. Thus we know that choosing actually happened and that the dinner order is an actual choice.
But, was the choosing "deterministic"? I don't know. Let's ask the customer. "Sir, can you tell us why you ordered the Chef Salad?". "Sure. When I saw the juicy steak dinner, I considered ordering that. But then I remembered that I had bacon and eggs for breakfast and a double cheeseburger for lunch. My doctor had advised me that I needed to eat more fruits and vegetables. So, I decided that the salad would be a better choice for dinner tonight." Just to be sure, we ask, "So those reasons
caused you to order the Chef Salad?" "Yes", he says, "I
could have ordered the steak, but I decided I
would order the salad instead."
So, it appears the choice was deterministic: Given those circumstances, he only
would have ordered the salad, even though he
could have ordered the steak. We did not observe him flipping a coin to make this decision, so we have no reason to suspect the choice was "probabilistic".
Another thing we did not see is any choosing happening prior to the customer opening the menu. The choice was not "preprogrammed" or "predetermined", but rather the choosing happened right there in front of us, in that specific place, and at that specific time.
Could we have predicted his choice in advance? Well, theoretically, yes. If we knew what he had for breakfast and lunch, and we knew his dietary goal for each day was to have more vegetables, then we might very well have predicted that he would order the salad for dinner. But our prediction would not be the cause of his choice. His own choosing would still be the cause.
We also may note that
past events reliably led him to that choice. His doctor's recommendation to eat more fruits and vegetables, and his prior choices that day, reliably led him to choosing the salad for dinner, even though he could have had the steak instead.