The key difference is that a Squelch is not a black mark on the account that stacks. If a GM applies a Silence then that goes on your permanant record, so to speak. Next one you get would double in duration.
That is why it is so important to get appeals in if a GM makes a mistake.
Also of note from a CS discussion yesterday, they now send out emails for Squelches and the wording is NOT logical. It will say silence and abusive chat when it is a spamming report squelch. Blizz is aware and the Forum Support Agents have sent the feedback on up to have that fixed, hopefully.
Yes they do. It is not common, but they will still close accounts. Mostly the ones that are botting/stolen. Enough penalties though can still get a normal account closed.
Samesies from what I can tell.
Just refer to the Silence article for a list of what you can and can’t do.