We may be living in increasingly secular times, but cosmologists and philosophers are vastly more atheistic than the culture at large. Is it not curious that the majority of the people who dedicate their life's work studying and thinking deeply about the big picture issues (origin of the universe, the nature of morality, free will, etc) are turning to atheism in droves? If the arguments for God are so strong, how are so many of them failing to see that?
Along the same lines, you say the first cause argument is treated with derision by many philosophy departments. But why is that? Might you entertain the possibility that it's treated with derision because it's not a good argument?
And this raises what I think is a critical question: Suppose you were decide that, after further examination, the first cause argument doesn't hold up. Would you then abandon your belief in God?
I agree that the existence of a first cause of some kind is logically necessary, and as such it must logically have some specific attributes, like being eternal. But I disagree that all attributes of the first cause are logically necessary, although they would be empirically necessary. And I definitely disagree that only God can fulfill the logically necessary attributes.
By "omniverse", I simply mean "everything that exists." Of course, it is possible there are things that exist which can't be proved by philosophy or anything else. Things that are simply inaccessible to us. But that doesn't mean we should believe in unprovable things, just because they are conceivable.
Much like a "mind", an "I" is just an abstract concept. And some philosophers argue it's an illusory one at that. I'm undecided on the matter myself, but inasmuch as "I" means anything, it represents my thoughts, memories, etc. In other words, my mind. I don't think using a different word changes anything.
I feel like you are avoiding the common sense usages of "simple" and "complex." "Simple-minded" is an actual phrase we use, and we don't mean indivisibly-minded. And when we say "chess is a complex game", we don't mean because it has so many different pieces. The mind of a turtle and the mind of a human are presumably equally indivisible. But would you not say the turtle's mind is simpler than a human's? Or at least has simpler capabilities?
As for the hypothetical serial killer, I think punishment for punishment's sake is pointless. Even with unlimited resources, we may not want to house him in the luxury mansion, for consequentialist reasons of reformation, deterrence, or even the victims' families' happiness. But if we knew housing him in the mansion would not change one single thing for the worse, then sure, why not? If there are zero trade offs except in one scenario the killer suffers more in the other scenario he suffers less, I think it would be immoral to choose more suffering.
"X is inherent in God's nature" seems like a catch-all to get out of tough problems. Goodness is inherent in God's nature, justice is inherent in God's nature, etc. But what is goodness? What is justice? Why, it's what God's nature deems it to be. This is an unfalsifiable loop, which I think I just demonstrated by way of hell. Eternal suffering is the most morally indefensible thing I can imagine, but if God inflicts it, and God can only act according to his nature, and his nature is perfectly good, then it must be perfectly good to inflict eternal suffering. After all, it's inherent in God's nature.
Interesting stuff regarding the Catholic Church's teachings on admittance to heaven. That's certainly not the impression I got when I was around the Church, but it's possible I wasn't paying close enough attention. In any case, it raises a few questions:
My sense is that the majority of people don't seek truth in any real active way. I think most people just absorb whatever default beliefs, values, etc are in the surrounding culture, and don't think too hard about them. This includes, of course, most Christians. So do these people not get into heaven?
And if they do get in, then the next bucket of people are those who do seek truth in an active way. I would put most scientists, philosophers, etc in this group. And it sounds like whatever their conclusions, right or wrong, they should get into heaven too.
So who does that leave? People who are actively seeking truth, sincerely believe Christianity is that truth, but reject it anyway, and refuse to ask God for forgiveness? This has got to be a rather tiny faction (especially of all those who have ever lived). Are these the only people who are in hell?
