A book that BIBLICALLY answers each of these questions that you're raising in favor of the Universal Restoration is called "The Universal Restoration" by Elhanan Winchester. You can probably find a copy at abebooks.com
for under $50. Perhaps a $20 copy. That book got rid of my last remaining questions about a belief in the Universal Restoration by answering each of these questions from the Bible that you've raised, and a few that you haven't yet raised like the supposed infinity of sin (mentioned once in Job), where the tree falls there it will lie, how punishment of short continuance serves to enrage rather than to humble and to discipline, the great ransom (in Job) that can't deliver, the Scriptures about wrath abiding on the unbeliever, Jesus saying that where I go you cannot come, unquenchable fires and undying worms, can anything less than endless damnation be sufficient to justify the expression of "Good were it for that man, that he had never been born," etc., etc., etc.
You're dealing with a perspective of Christianity that goes back to the very beginning of Christianity and that experienced the true Reformation at the time of the Reformation. That you never found adequate answers at this website to your questions doesn't mean that they don't exist. I'll give you additional arguments that have been proposed since the Reformation against the Universal Restoration if you'd like, that never have been sufficiently defended by believers in endless damnation when the message of the Universal Restoration was allowed to shine in it's truest light. We're not intimidated by a single one of these questions, and most of us have Biblical answers to all of them, rather than speculative answers. Let me help you construct additional threads that would likewise be refuted with as much or greater ease
How about the argument that though aion may be bound to time here, that that doesn't mean that it's bound to time in the future world?
How about the argument that tries to claim that Philippians 2 will only be fulfilled by force?
What about the fallacy built upon the eternal co-existence of good and evil that as we're perfected in righteousness, so also evil in the wicked is grown up to a body in them, and it appears as difficult to reform and bring them off from their vicious habits, as it would be to draw the saints in light from their adherence to virtue and goodness?
How about the nonsense that All doesn't always mean All in the Apostles writings?
What about Esau? Judas?
The impassableness of the great gulf?
How can these people know more than the rest of the Body of Christ?
The doctrine of endless punishment being proposed to be the greatest possible restraint upon sin?
If it's not a plain doctrine to all, then it cannot be a doctrine of Scripture at all? (oh, please toss this one at us
God sware in His wrath that the Israelites should not enter into His rest.
Our Saviour has said that the night cometh when no man can work.
The characters of all fixed and unchangeable after a certain point of time, viz., he that is unjust let him be unjust still, he that is filthy let him be filthy still, &c.
Those who add or diminish have the plagues added to them, or their part taken out of the book of life.
Sinners in Hell supposedly under a greater and greater pressure to commit more wickedness.
All of these and many more have been Biblically answered with the absolute greatest of Biblical ease in every century since the Reformation.