Great discussion of a difficult topic
Why question the existence of hell? It's good to question to get a deeper understanding, but you should be careful to not change your doctrines based on shifting cultural views. That can lead to mistakes like the Crusades.
Sinning puts holes in your soul; grace through the sacraments re-creates and fills the soul.
Hell is for souls that have uncreated themselves so much that they are no longer human, no longer God's image bearers. Perhaps heaven would be worse for those that are uncreated.
If we are wholly separate from God, we would not exist. Aquinas says God is the first cause, not once as a first domino, but moment-to-moment as a broom sweeping leaves.
What about children?