Alright I skimmed through that video and I have to say that you are doing a lot of incorrect plays.
Off the top of my head:
*Constantly over extending on to the board against Priest with 3 HP minions then getting clapped by Excavated Evil. You don't need to do that, just hero power spam when you have two minions and they have none.
*Improper usage of Flametongue, Zealous already pointed out some issues but more importantly you mess up placement. You want to play Flametongue on left side and then new minions on the left of that so that when you spawn totems they spawn on the right side of the Flametongue.
*Improper usage of Rockbiter. You occasionally use Rockbiter when you don't need to, it could've been better saved for Doomhammer later on. Only use Rockbiter when you have to.
*Mismanagement of overload. You constantly put yourself in bad overload situations when you didn't need to. An example is turn 6 you had board with Doomhammer and Thunderbluff in hand, you played Doomhammer and then next turn couldn't do Thuderbluff plus hero power.
*Improper usage of Lightning Storm. You should always hero power to have a chance at rolling Spell power Totem then use Lightning Storm. There were many chances for you to do this but you failed to do it and then got punished when your LS didn't kill much.
*Speaking of LightniNG Storm, in game two you were against Warlock and during Mulligan phase you had Lightning Storm and two Troggs in hand. You discards the LS AND a Trogg. That was a big mistake as it was likely to be Zoolock (if it wasn't then you were favored to win anyway so keeping LS wouldn't have mattered) and of course you get punished as its a Zoolock and you don't have LS. That game you would have won if you kept at least the LS.
*You are too trigger happy on the Hex, need to save it for bigger targets.
There were quite a few matches in there you had no business winning but won anyway because of Shaman. Lots of more subtle misplace involving trading, board positioning, mulligans and decisions on how to control their board and manage your own.
It's a ruthless analysis but that's how you get better.
But everyone has been going on and on here about how any old Shaman deck should be godly? Make up your mind people, is the problem my deck or isn't it?
How about
this one then, that's got two Flamewreathed Faceless in it?
Well every competitive Shaman deck has Faceless so that was the main assumption.
Thouhh the real problem are the plays, less so the deck.