Question: "How do you square Luke 13:1-5 with the idea that Hell is not experienced by all outside of the Church in the same way?"
Luke 13:1-5
The passage in Luke 13:1-5 really does not address the question of whether hell is experienced by everyone the same. According to the commentary of Blessed Theophylact, the Galileans that were slain by Pilate were the followers of a man named Judas of Galilee, who was stirring up rebellion against Rome.
So when told about those who were killed, Christ asked the people: "Suppose ye that these Galilaeans were sinners above all the Galilaeans, because they suffered such things? I tell you, Nay: but, except ye repent, ye shall all likewise perish."
His point was that unless they repented, ceased stirring up rebelling, and served God, they would all likewise perish. And then he mentioned another incident: "Or those eighteen, upon whom the tower in Siloam fell, and slew them, think ye that they were sinners above all men that dwelt in Jerusalem? I tell you, Nay: but, except ye repent, ye shall all likewise perish." According to Blessed Theophylact, this tower falling on the 18 at Siloam was an image of what would happen to all the people of Jerusalem when the Romans would destroy it in 70 A.D.
Differing Degrees of Punishment
That there will be different degrees of punishment in hell is made clear by many passages of Scripture:
"And that servant, which knew his lord's will, and prepared not himself, neither did according to his will, shall be beaten with many stripes. But he that knew not, and did commit things worthy of stripes, shall be beaten with few stripes. For unto whomsoever much is given, of him shall be much required: and to whom men have committed much, of him they will ask the more" (Luke 12:47-48).
"My brethren, be not many masters, knowing that we shall receive the greater condemnation" (James 3:1)
"Woe unto thee, Chorazin! woe unto thee, Bethsaida! for if the mighty works, which were done in you, had been done in Tyre and Sidon, they would have repented long ago in sackcloth and ashes. But I say unto you, It shall be more tolerable for Tyre and Sidon at the day of judgment, than for you. And thou, Capernaum, which art exalted unto heaven, shalt be brought down to hell: for if the mighty works, which have been done in thee, had been done in Sodom, it would have remained until this day. But I say unto you, That it shall be more tolerable for the land of Sodom in the day of judgment, than for thee" (Matthew 11:21-24).
"Of how much sorer punishment, suppose ye, shall he be thought worthy, who hath trodden under foot the Son of God, and hath counted the blood of the covenant, wherewith he was sanctified, an unholy thing, and hath done despite unto the Spirit of grace?" (Hebrews 10:29).
Differing Degrees of Reward
The Scriptures also indicate that those who are saved will likewise receive different degrees of reward:
"For the Son of man shall come in the glory of his Father with his angels; and then he shall reward every man according to his works" (Matthew 16:27).
"Now he that planteth and he that watereth are one: and every man shall receive his own reward according to his own labour" (1 Corinthians 3:8).
"Every man's work shall be made manifest: for the day shall declare it, because it shall be revealed by fire; and the fire shall try every man's work of what sort it is. If any man's work abide which he hath built thereupon, he shall receive a reward. If any man's work shall be burned, he shall suffer loss: but he himself shall be saved; yet so as by fire" (1 Corinthians 3:13-15).
"And, behold, I come quickly; and my reward is with me, to give every man according as his work shall be" (Revelation 22:12).
Conclusion
The Gospel of John tells us that Christ is the "true Light which gives light to every man coming into the world" (John 1:9). And Christ made it clear that we will be judged according to what we have been given: "unto whomsoever much is given, of him shall be much required: and to whom men have committed much, of him they will ask the more" (Luke 12:48). So clearly, those who have been given less will be held accountable for less. So those who have never been in the Church, and who go to hell, will be judged less harshly than those who have been in the Church, had the fullness of the Faith, and yet either did nothing with it, or disregarded entirely, and lived actively wicked lives. Exactly how those differing degrees of rewards and punishments will be manifested, we cannot say. But we know for sure that on the day of judgment, no one will be able to say that anyone received an unjust punishment, but will rather say "the judgments of the Lord are true and righteous altogether" (Psalms 18[19]:9).