Yep, good points. Even though the Declaration holds no legal bearing, they will try to point to that (but ignore the Treaty of Tripoli, LOL). Though I think some of today's Christopaths would probably burn the Deist Founders as heretics if they had the chance.
Lastly, yes, the Founders were well aware of the worst impulses and excesses of religion that is given any power, given that the Inquisition was still going during their lifetimes. Given that many were Deists, surely they had to know that kind of heresy [1] would not be tolerated by the most fanatical of xtians.
[1] - Heresy literally means "choice". Kind of ironic that today's right wing that has co-opted terms like "liberty" and "freedom" are the very ones that would be America's own Morality Police, zealously trying to stamp out any and all heresy (choice) if they had the chance. Also, the same bunch constantly concern troll over things like "Shariah Law" - more irony, I guess, since they only differ on small matters of doctrine dealing with unverifiable superstitions, but don't really differ at all on the outcomes and the methods on who should be subjugated (women, LGBTQ, the "other" faiths).