My point is Scripture only presents Christ as God's Son prior to the Cross.I really do not know what your point is. Monogenes does not mean "only" it means unique.
I see you did not address how we are descendants of God, if Adam is not God's son.
Also, my point is that monogenes also means only child (or only legitimate child) when used as a noun. As an adjective it means unique or"one and only".
Any way you look at it, prior to the Cross God sent His unique, one and only, Son.
My other point is you have argued that Adam was God's son by adding to Scripture and language.