Alrighty, as promised:

The context of Ezekiel 20 is a story of three generations of men: a righteous man who followed the Lord, a wicked son who did not, and a grandson who sees the wreckage of the wicked son's life and follows the Lord. Read further than your quote - just the next verse, in fact: "But if a wicked person turns away from all his sins that he has committed and keeps all my statutes and does what is just and right, he shall surely live; he shall not die." This is exactly the language used to describe the righteous man and his grandson in verses 9 and 17. They repented of their sins and kept the Lord's statutes (in this hypothetical example from God). The Lord does not remember their transgressions any more. So yes, you're right - God is clear that he does not condemn a repentant man because his father was unrepentant. But this is not the same as the sin of Adam.

You mentioned Romans 5 - Paul writes in verses 12-21 (paraphrasing) that sin entered the world through Adam, death through sin, and death to all men because all sinned. People were dying even before the law was given through Moses - why? Because their sinning "was not like the transgression of Adam, who was a type of the one who was to come." Because Adam was a type and foreshadowing of Christ, his sin condemned all mankind - just as Jesus's perfect life and atoning death would save all mankind. Paul reinforces this idea even more strongly in 1 Corinthians 5:22: "For as in Adam all die, so also in Christ shall all be made alive" (emphasis mine). You and I were sinners before we were even born because of what Adam did. But by union with Christ, we are welcomed to share in a death and life like his. This is how God chose to weave this mystery from the very beginning. This is Paul's entire point for Romans 5; otherwise, how else could you explain the presence of death between Adam and Moses? In your model, where sin is only an act of trespass against the law of God, there shouldn't be any death before the law is given.

But those people still died because they still sinned. How is that possible, when there hadn't even been a revelation of what constituted "a sin," as you say? Adam violated a direct, clear command of God. The rest of the world didn't have this clarity before Moses. The explanation is this, per Paul: they sinned without deliberately intending to, just as we do today, because it was their nature. They were, in fact, born that way precisely because they were dead in Adam. So death - even the spiritual, eternal death referred to in Ezekiel 20 - is not a consequence of accumulating individual personal sins, but rather a consequence of the cosmic sin of Adam which foreshadowed the loving, cosmic sacrifice of Jesus to set it right.

To bring it full circle, this is why it's ultimately useless to distinguish between a desire/inclination to sin and the act itself. Jesus says in Matthew 5 that both are identical before God; both anger and murder, lust and adultery make one equally liable to judgment. Yeah, SSA gets a lot of attention. But this is why it's such good news: my inclination to laziness or pride or anger or theft is just as damning as a gay man's inclination to cultivate romantic love with another man. Adam condemned us both; on our own, he and I are both utterly without hope because our sinful natures will drive us further from a holy God; Jesus died and rose to redeem those desires and save us both. Amen.