re: Would you refuse to speak to your adult kids if they changed their religious beliefs?

Neither would be cut off. Atheists can be irksome especially if it is an outright hostility, but if it's the ole, I don't believe in God thing and they aren't pushy about it, probably a phase.

Mormons are a bit more problematic from a theological standpoint but the practicing ones I know are pretty tolerant and are genuinely good people.