Re: reason and reality -
That would be a first for these folks.
Re: "rational egoism" -
There is nothing truly rational about egoism. Or egotism, for that matter, which is what these movements ultimately and inevitably end up boiling down to.
Rational egoism is rational, by definition. Irrational egoism is neither rational, no moral. Just because some may confuse rational egoism with egotism and irrational selfishness does not invalidate the ideal. A society where each individual is free to (and encouraged to) act in their own best self interest, so long as ALL individual's rights are protected and respected, is exactly what the founding fathers intended.
As for religion, they knew very well that to protect freedom, it was to be kept a private matter outside the realm of politics and government. Government, they understood, amounts to sanctioned force (or enforcement).
The First Amendment: "Congress shall make no law respecting an establishment of religion..."
-- "The legitimate powers of government extend to such acts only as are injurious to others. But it does me no injury for my neighbor to say there are twenty gods, or no god. It neither picks my pocket nor breaks my leg." - Thomas Jefferson
-- "That if there be but one right, and ours that one, we should wish to see the 999 wandering sects gathered into the fold of truth. But against such a majority we cannot effect this by force. Reason and persuasion are the only practicable instruments." - Jefferson