No you are missing the point.
This is, simply, precious.
I can construct a concept about what the rusty metal object is and it doesn't matter if I constructed it using the imagination or not. It is what it is because it exists in the external world and what it is, is unknown.
Right. There is practical, empirical, non-anecdotal, objective, testable evidence of its existence.
I can also construct a concept about the unknown object which exists in the external world, which is the origin of our known world. If it exists it is a correlate of the rusty object. If it doesn't exist, then the issue of our origin from nothing raises its head again, and we're back at the beginning.
Right. If there were objective, empirical, non-anecdotal, testable, objective evidence, the thing about which you have constructed a concept could be said to exist in the "external world". Without such, imaginary thing is imaginary.
"The issue of our origins" is not resolved by imaging "agency", then imagining 'gods' to explain that constructed concept of "agency" where there is no agent.
Essentially the issue is whether our known world is (to an extent) a result of intelligent input in nature, or that there is no intelligent input.
It can be empirically observed that there is intelligent input in nature,
...and this is where your structure founders.
Please demonstrate (with empirical, practical, concrete, non-anecdotal, objective evidence) the "intelligent input" in "nature".
This should be fun.
therefore intellectually it is rational to consider that nature includes intelligent agency and god falls into the set of intelligent agents.
It is "rational" to consider that "nature includes intelligent agency" because you assume that "nature" requires "intelligent input"?
Circular arguments are, at least, easy to circumscribe. They can even be fun. They are not, however, productive.