Ah right. I missed the fact that you mentioned Feser. I examined the argument first, but shouldn't have bothered since you mentioned him. I've read his blog, and it's chock full of the bizarre reasoning such as above.
> <lots of words>
> A implies B without a single shred of justification
> <some more words>
> Therefore Jesus
I'd recommend not bothering with any of that. It's honestly not worth anybody's time except as a curio for how to dress up nonsense to look reasonable.
> Because there must be a root cause, this root cause must be jesusy
The logic is in "not even wrong" territory. Why does being "purely actual, absolutely simple or noncomposite" imply "fully good"? Because you've abandoned reason and are just making up definitions. Define "good", please and thanks, and how that has any connection at all to a "root cause", however you want to define it.