As for "Buddhist Christians" one of those views of who God is must be completely metaphorical and the other must be historically true. They can't both be true.
I would tend to agree with you here, yet I also see a lot of commonalities in Buddhist and Christian perspectives too. As you say, Buddhism does provide some very helpful food for thought even if a Christian cannot truly be a "Buddhist Christian" (or vice versa).
Personally, I found de Chardin's writing to be too much word salad. It was sort of inspiration witout content.
This is why I regret that he was unable to publish during his lifetime. A genuine scholarly dialogue would have forced him to clarify many of his mystical concepts or consigned him to irrelevancy. As it is, he is stranded somewhere between.
The problem is when we start to confuse wisdom and morals with salvation. Chardin is an example of how bad origins theology can be of one piece with a complete corruption of the Gospel -- which occurs at the point where the basis for true salvation is denied:
A diatribe from one highly opinionated critic who has to admit the Church never found Chardin to be heretical. Furthermore, not a word in his list says anything of Chardin's beliefs about Christ, the atonement, the resurrection or salvation. So it doesn't make the link you allege between "bad origins theology" and "complete corruption of the gospel."
Obviously, the Church did have troubles with Chardin's work--hence the refusal of an Imprimatur. But this is not evidence that he questioned Church dogma at all.
Not every Christian makes this mistake, but de Chardin replaces the resurrection and the Romans 10 confession with a different path to salvation. And he does this in part with ideas from Darwin and Eastern religion. Others can remain Christian and traffic in these ideas to their benefit.
I am certainly not here to defend everything Chardin said. I don't see him as a strong theologian, but as someone struggling, not always successfully, to bring together the various extra-biblical sources of truth he was discovering with the truth of the Christian faith. I think he does overstate himself sometimes. But I don't think his weaknesses amount to a mandate to exile him from the Christian community.
Having found a new basis for salvation, Paul is pretty clear about how to regard this teaching. The man is anathema (or at least his teachings are).
A step in the right direction. Perhaps some of his teachings are anathema. Though let us note that the Church has never formally defined any as such. But that doesn't mean the man is. And it was the condemnation of the man I questioned.
I also do not find a basis for claiming Chardin found a new basis for salvation. That looks to me more like a misinterpretation of Chardin than a teaching of Chardin.
You know where this pursuit of the "omega point" leads? To people shivering in the bushes, clothed in fig leaves, hiding from God and waiting to die.
Given that the Omega Point is Christ, I think you are mistaking where pursuing it will take you.
Perhaps worse yet, the "consciousness" he wants is to be "like the most high."
"I will ascend above the heights of the clouds; I will be like the most High."
I think you are equivocating again. The prophet's description of ambition does not pertain to expansion of consciousness at all.
And if a Christian is not seeking greater conscious awareness (especially of God) and to be more and more like Christ who is the express image of God, s/he is surely not maturing in the faith.
In short there are ways of seeking to be like the most High that are rebellious and blasphemous and ways of seeking to be like the most High that are positively enjoined on us. "Be perfect as your Father in heaven is perfect." "You shall be holy to me, for I the Lord am holy." "Beloved, since God loved us so much, we ought also to love one another."