No you normally don't put 2 mana tides in the deck, but you definitely want one in. It provides a net benefit if you can get them to spend a card to remove it.
I don't think shaman always needs it, but this deck benefits greatly from it.
edit:
Also... man, I am also loving having added lava burst to the deck. The deck can sometimes have trouble taking out 5 health minions, and then sometimes just that extra burst can really help even though I already have doomhammer + alakir and rockbiter/flametongue combos.
It just helped me win a match against the most hated priest who had a cabal shadow priest and a 4/4 on board. I played azure drake to take out the 4/4 with lightning bolt, topped a lava burst and could clear board. Next turn I still had enough mana to fire elemental or black knight etc.. So nice.
edit2:
lol just had a match vs one of those all face all day hunter decks as shaman and I almost lost due to a disconnect. I mean, I had this thing wrapped up. Doomhammer and 2xrockbiter in my hand, a way to get him down to 16 the next turn, 2 taunts and 2 other minions on the board to ensure I get that done, and even a lava burst to follow up in case I don't manage it.
Then I disconnect... I come back to an empty board an 2 minions on his side. I see it is my turn, but nope it is not it is over. He brings me down to 5 hp... he is at 18. I could win if I doomhammer and x2 rockbiter and lavaburst with full 10 mana. But he played loatheb. FF.....ck. But I had picked up alakir. Hit face once, removed one minion. And rolled a taunt totem. So clutch, however I guess I would have lived by 1 hp if the 2 attack minion could hit face and then hero power.
Then I just did my doomhammer + 2x rockbiter.
It must suck to lose a match up that way. He had the holy grail of like 2-3 turns to do whatever he wanted. And he still lost.