I didn't read any futher then your first point alexi:
"""1) This requires that all babies are sinners from birth and are only saved if they later "accept the sacrifice of their Lord and are baptized." All others remain stained with the original sin and destined for destruction. Till recently, unbaptized infants were not buried in consecrated ground because they were believed to have died in original sin. Saint Augustine himself is quoted as saying:
"No one is clean, not even if his life be only for a day" A dictionary of Biblical tradition in English literature, p.577).
This, however, contradicts the words of Jesus himself
"But Jesus said, Suffer little children, and forbid them not, to come unto me: for of such is the kingdom of heaven." Matthew 19:14 (also Mark 10:14, and Luke 18:16).
So Jesus himself is telling us that children are born without sin and are destined for heaven without qualification. In other words, no one is born stained with an original sin."""
You have the wrong "interpretation", if I would even call it that. He isnt talking about sin. Jesus is talking about how in the kingdom of heaven people will be likened unto babies that will come to Jesus for teaching and such. He rebukes the disciples because they didn't understand the importance of children and in actuality, we will all be like unto children in the kinddom of heaven, receiving eternal instruction and healing from the Father through the Son.
blessings...