Just try to be as aggressive as possible. The only real way to increase your chances of winning that matchup would be to add Eater of Secrets to your deck, which would ruin your consistency against other decks.

Not essential, but it’s definitely worth having in the deck. It helps put your opponents in range, especially the the turn after you play Gul’dan, but it also really helps keep you alive. There’s a lot of self damage in this deck. Alex is an extremely safe craft; If you craft her and don’t like her in this deck she’ll be useful in others.

Lyra is much better with Radiant Elemental, and Radiant Elemental ruin Barnes and Shadow Essence. This deck is also missing Power Word: Shield and other spells that enable Lyra cheaply.

You could replace it with any of the cards listed in the substitution section.

Silence is good, it’s listed in the substitution section. To put in a silence card I would take out Spirit Lash or the second copy of Potion of Madness.

Barnes is very important for this deck, without him you’re relying solely on Shadow Essence to cheat out your big minions, and best case scenario you’re only accelerating them by a turn or two. You could try running it without him, any of the cards listed in the substitution section would be suitable enough.

Bloodreaver gives the deck its staying power; you could still play the deck without it, but it probably wouldn’t be as good. You could try falling back on the Defender of Argus/Sunfury Protector style of play, and if you have it you definitely want to put Jaraxxus in.

You could, Harrison might be a bit slow, and the deck has lots of draw already. If you don’t have Gluttonous Ooze, Acidic Swamp Ooze is probably the best replacement. Also, if you’re not running into a lot of weapon-heavy decks you could run something else entirely.

Personally I would put in Spellbreaker. There are a lot of juicy silence targets out there right now, primarily Spikeridged Steed. Dread Infernal works as a big minion that has synergy with the deck, and Corrupting Mist would help with the aggro matchup.

I wouldn’t say Alex is absolutely necessary, but it’s great tool to keep you in the game against aggro if you’ve made it past the early game with low life. It also helps race control decks.

I haven’t heard anything, but if they’re only available in the Blizzard store I imagine you’ll need real money. Still a good value by Hearthstone standards but it is a bummer you might not be able to use your gold. There’s a new set coming out though, so extra gold is good to have right now at least! I think a Wild tier list is a good idea.