I’d note that simply labeling it a non sequitur doesn’t clarify where the reasoning breaks.
Apologies. To me it was obvious. The issue that, to me, makes it a non sequitur is your treatment of "will" or "consciousness". It is not present in the premises. Everything is "unchosen". Yet your conclusion asserts otherwise. Non sequitur.
If you believe further premises are needed, I’d be interested to know which ones you think would bridge the gap.
I don't think any can bridge the gap without begging the question which you're trying to achieve. You'd need to have premises that assert that creation requires a consciousness, for example. But then you'd get into matters of whether such premises are true, or just a matter of faith.
Ultimately, any valid deductive logical argument that tries to conclude "God" as the only possible answer will, in my view, be guilty of either informally fallacious logic, be it circular reasoning, or the soundness will be called into question. That is notwithstanding formal fallacies, such as ignoring "not-God" (i.e. an existence absent the need for God) as a possible conclusion that also fits all the premises.
The inference isn’t from ignorance, it’s from what is already known. Our unchosen existence is a clear fact, and if all existence is unchosen, then the entire chain consists of dependent realities that cannot ground themselves. The inference to a necessary, independent cause follows standard causal reasoning. And the idea of will arises from the evident order and purposive structure of existence, which suggests intentional rather than blind causation.
Thank you for the further clarification to your thinking.
As DaveC has succinctly stated: you drop the ball with regard will, and consciousness - your "intentional rather than blind causation". There is
nothing in your premises that make this a valid conclusion.
Maybe you would need a premise such as "all causation is willful", or "existence has a purposive structure". I mean, you'd quite possibly be tying yourself in knots, or overcomplicating the resultant argument, but it is almost certain that any such premise that subsequently allows you to validly conclude "willful", or "intention", would be challenged and, by those of us who don't believe, would be deemed unaccepted. And thus your argument would only really be valid for someone who already accepts the argument.
Anyhoo - as an argument for God, it needs some work, for sure. And you'd be merely adding to a long list of such arguments that are either not accepted as sound by anyone other than those who already accept God exists, or are invalid.