While there is a lot of truth in what you are saying, there is also a lot of room for misinterpretation. Can you please clarify whether or not you are promoting the doctrine of sinless perfection?
The new man is "created according to God in true righteousness and holiness" (Eph 4:24), but the flesh "grows corrupt acording to the deceitful lusts" (Eph 4:22). That is why we who have been born again are told to "put off the old man" and "put on the new man" (Eph 4:22-24) and that walking in the Spirit is the only way to not fulfill the lusts of the flesh (Ga 5:16).
I don't know any one who teaches the doctrine of sinless perfection. I think it was derived out of an ignorance of the power of the new birth and used as a disqualifying epithet to relieve the carnal Christian of his inability to live as a true believer. This a label that has been thrown at me and others as a misdirect.
There are those who know they are corrupt to the bone but as a born again Christian believe God that their old nature of sin has been crucified and buried and therefore walks in newness of life. His life is one of continual obedience to all the Father's directions. One who is born again never violates his conscience, for that would render him dead. Therefore his fallen nature is ineffective. Sin and the Adamic nature have no dominion over him, for he is a new creature and a partaker of the divine nature by which he has escaped the corruption that is in the world through lust. This cannot be faked or worked up in the flesh. One cannot get to heaven by white knuckling it. When the weakest believer places the full weight of his faith upon his merciful redeemer, he will overcome and it will be as though it was a natural impulse. The devil is no match for a soul like this.
You wrote "created according to God in true righteousness and holiness"
This is not of his self, but it is the righteousness and holiness of the Son with whom he is one.
Eph 4:22 "That ye put off concerning the former conversation the old man, which is corrupt according to the deceitful lusts; And be renewed in the spirit of your mind; And that ye put on the new man, which after God is created in righteousness and true holiness."
"renewed in the spirit of you mind" the mind of Christ which every true believer has.
In Romans 6:6 Paul writes "...the old man and the body of sin were destroyed." (Paraphrased). He is admonishing the believers to walk by faith. That is to say your Father believes you are dead and so should you. It is already true and you should 'put it on'. According to your faith it will be unto you.
You wrote, "So, sinless perfection exists only in the new creature created when Christ comes to live in a persons heart, not in the body in which he currently lives."
I don't understand how you can have a heart outside of the body in which you live.
In Hebrews 11:40 we read, "God having provided some better thing for us, that they without us should not be made perfect."
This word 'perfect' in the lexicon equates it with 'complete' or to "add what is yet wanting in order to render a thing full"
We have come to the final days and the Father is finishing the work in us. This 'better thing' will complete the believers in preparation to leave the planet, and demonstrate that if the patriarchs who came before us had lived in our day they too would have come to this completion. In that God is completing that work in us He covers all those who have gone before with the same completion. They are 'made perfect'
Anyone who is hoping or claiming perfection is not well in their mind. Aside from the fact that one would have to be looking at their self to see if they were perfect or not. The true believer keeps his eyes on the Father and it is the Father's prerogative to declare something perfect.