Hearthpwn

Like others said I used to use emotes politely when I was new, but this isn't a polite game.  Almost everyone  now is a raging troll who will spam greetings and wait until rope to do lethal damage to you, then add you as a friend to tell you how awful you are and how you should probably kill yourself. 

Usually I'll only do it back when they are thinking until rope when they only have 1-2 cards on a empty/near empty board every single time.  If you have to play 3-4+ cards that turn, sure, think all you want, but if you literally only have one card you can possibly play, it shouldn't take you that long to decide between "play it" and "don't play it".

Could you please post a mulligan guide for this? 

If you are losing every game with a deck, chances are it's not the deck's fault.  Unless you get terrible draws or are at very high ranks you should beat most of the mentioned decks at least half the time.  Of course if you let them fill up the board you're going to lose, but if you play the deck right you should either win before they can and/or you should be able to maintain board control to prevent them from doing it.

After climbing from 16 to 9 with this deck I've hit a wall of almost all shamans running with 2xDevolve.  It easily wipes out all our cheap minions that we rely on for this deck to succeed.  Any ideas on how to counter it?  Even being careful and trying to play around it I still am forced by their board pressure to play minions and eventually run out.

It's definitely a problem but at least in my (limited) experience with this deck, you should be able to clear any big threats with your big silenced minions, or hide behind taunts.  The whole idea of the deck is to get board control early and maintain it until you can kill them in one turn.

I just started with this deck and I'm on a win streak from mid 15 to 12.  It took a while of practicing in casual to get it right but when it works it works really well.  The only deck I had trouble with in practice and in real play so far was decks with much more removal than you regularly see on ladder.

While I haven't needed it yet, I would like to try and work in a Excavate Evil just as insurance for bad initial draws - but of course the more insurance against bad draws you include, the more likely it is you'll get a bad draw.