I don't build a theology around one or two verses, nor do I approach scripture with a theological prejudice.
If the Romans 5 verses you cite teach universal inherited sinfulness, then they also teach universal salvation, and you don't believe that. If, however, they teach that those who follow the way of Adam die and those who subscribe to the way of Christ live.
Rom 3: All have sinned! Look at it; it's a verb...sinned. The all being addressed did it: sinned. Are you claiming that all unborn humans commit sin? Maybe they lust and just cannot verbalize it.
Silliness aside, of course Paul's argument in the first chapters of Romans is that Jews and Gentiles need a savior alike. And here he quotes the Psalmist that God looks down on the earth and see that everyone "turns aside," "deceives with their tongue," curse with their mouth," etc. Now think about it...do you really think what's under consideration here is unborn babies doing all these things? Or do you think it more reasonable to understanding that what's being talked about is those who DO THOSE THINGS LISTED?
Sin is lawlessness (1John 3:4), not a genetic disease.
I noticed you didn't address the passages I posted, as I did yours - you just posted others and claim they disagree.
Don’t confuse sin with immorality. Sin is simply missing the mark of God’s Plan.
It wasn’t God’s Plan for Adam to have sinned in the Garden.
The sin is passed genetically from the male to each generation of human.
All humans has missed the mark of God’s Plan. None are qualified to provide an appropriate sacrifice for that which they denied God, our spiritual fellowship, because we are all spiritually flawed.
Only Christ Jesus, in His perfect humanity was qualified to perform that task.
The splitting of the veil in two and the Resurrection bear testimony to this success.