Very good points. One minor correction, if you will, for one of my essays research on Britannica.com revea;ed that yes, the Founders identified nominally with Christian denominations from Roman Catholic to Universalists to Quakers - https://www.britannica.com/topic/The-Founding-Fathers-Deism-and-Christianity-1272214
It's a common error, but doesn't take away from your point undergirding freedom of religion - since today's general classification of "Christian" has a plethora of meanings to a whole menagerie of different folks.