[Judy Waytiuk]

I don't actually need lectures, but thanks for the thought. the word succumbed in this context means died. And yes, I know all the stuff you've listed--I've been keeping salt tanks since before people in North America even knew you could keep live corals!(and to this day i feel FOWLR tanks miss out on a lot!)-- and even taking all the precautions possible, you can still get a bout of ich in your tank.
All it really takes is introduction of a new coral that may have a few stray trodonts on the rock it's attached to.
If you read my post, it clearly says the tang was the only fish to show any sign of ich. In two months of recurring bouts of ich, it was the only fish to show ich-- the others, not a single spot. so the tank, minus the now dead tang, appears as healthy as ever.
Needless to say, I will be watching the other fish as closely as I have been for some time.
I disagree with you regarding copper. It has to be VERY carefully administered, yes. Nothing, absolutely, nothing, that you use in the way of equipment with a QT tank in which you use copper can be permitted to come in contact with your display tank.
But it remains the gold standard for guaranteed ich cure. I would love to know the brand names of the "other meds" you mention that are reef safe and that work. If you mean Kick Ich-- HAH! might as well shred twenty dollar bills into your tank for all the good THAT stuff does (I used it once about two years ago. Useless.)
a PS re cleaner wrasses: it is now commonly accpeted among the experts that cleaner wrasses do NOT clean up ich. They clean up the damaged and dead surface skin that's been damaged by the ich. They do not actually clean off the ich spots.