Hearthpwn

Face is the place, done... just kidding :) Sure you want to deal as much dmg to the face as possible, cause you get out of steam really fast, don't be afraid to trade to keep your better minons alive, but always.. really.. ALWAYS make sure if you have leathal, the most matches were decided in turn ~6-8.

Yeah and well, try to keep your minions alive to get a huge board, don't overextend as long as you opponent had not played any board clears yet, and.. shamans are pretty good in ruining your day, like seriously.. shamans.. 

Cold Blood is your bread and butter in the early- and lategame, when you have about 2-3 minions out in early game, don't be afraid to use it on a ~2HP creature.

Also buff your minions equaly, playing around board clears is your main goal, Shattered Sun Cleric is pretty good to bring your minions out of kill range. 

You really want to go 2nd with this deck, you have a bunch of 2mana Combo cards and The Coin is helping alot.

Always Mulligan: 
Hard mulligan for one Backstab, this can improve your early game by ALOT! And well the usual 2 drops, Defias Ringleader, Jade Swarmer, Loot Hoarder

Additional against Aggro:
Bloodsail Raider, Eviscerate, Jade Shuriken.. sure Bloodsail Raider is way better after you equipted your Assassin's Blade, but its also a solid 2mana 2/3 drop which can take 1-2 hits for you in the early game. 

Druids & Handlocks:
I faced alot of Druids in this rank spectrum, aaaand suprise SUPRISE! Not every druid is a Jade druid, Sap saved me quite alot of times, I saw alot of this games..
(Me going first, doing nothing..) Druid turn 1: 
Innervate -> Innervate -> The Coin -> Dark Arakkoa -> My Greetings!
Me: Sap.. 
They mostly end up doing nothing in the following few turns, and me having a huge board and winning the game. :)

You might been asking now: Okay, but whats with Handlocks? Shouldn't I keep my Sap for them aswell?

Answer: Kinda.. you can keep it, if you feel comfortable with it, but Sap is most powerfull when the Handlock comes to lethal range and starts taunting up like a mad man. Assassinate + Sap + Cold Blood won me the most games against Handlocks on turn 8.

Allright, if you have one or more of these: Edwin VanCleef, Shaku, the Collector, Aya Blackpaw, Gadgetzan Auctioneer .. well I have some good news for you, you can put them in your deck and I will recommend some replacements :)

1x Assassin's Blade / Assassinate: 
-> Edwin VanCleef, Aya Blackpaw, Gadgetzan Auctioneer

The 2nd Assassin's Blade is probably the biggest weakspot of this deck, the idea of it is, to guarantee to draw at least 1 of them till turn 5, but the 2nd Assassin's Blade can very likely turn out to be a dead draw if drawn in the early stages of the game. 
Same with the 2nd Assassinate, it is just a very expensive removal, drawn in the early game can really throw you back. But anyways, if you plan to remove one of these cards, I would recommand replacing the Assassin's Blade, since Assassinate can still help you in the later stages to deal with bigger creatures.

Bloodsail Raider / Jungle Panther / Shattered Sun Cleric: 
-> Edwin VanCleef, Shaku, the Collector 

I will not go to much into detail on this one, cause all of these cards worked very well for me, but if you have Edwin VanCleef or Shaku, the Collector, sure feel free to replace them with these.

Honorable Mentions:
 Year of the Mammuth is almost here so I didn't cover cards like:
Tomb Pillager, Unearthed Raptor, Sylvanas Windrunner or Ragnaros the Firelord, etc.
The rotation is just about to happen, so I've found it unnecessary to test em.

N'Zoth, the Corruptor turned out to be just WAAAAAAY to slow for this deck, even with Aya Blackpaw.

I strongly recommand to craft Azure Drake, you will get you dust back for it soon, you can replace them with 2x Kobold Geomancers, but I don't recommand doing that, Azure Drake is just too good,.. solid 4/4, spellpower, draw, what do you want more?

Defender of Argus is a really strong card in this deck, won me many games, even against pirate warriors, since you lack of healing or taunts, but heaving alot of small creatures, Earthen Ring Farseer is probably the only good replacement for him (or Sunfury Protector, if you got her in a pack) :)

Sure there are better cards which could fit into this deck.. but I simply don't have them, and thats why I also like this deck so much, If you have any suggestions for cheap card replacements, let me know in the comment section bellow! <3