Hmm, do I want to play the Serious Meta Deck (tm) that just doesn't die against aggro OR lategame-oriented decks, or do I want to play a stupid, fun deck that only works against those lategame decks, and only if I don't die...? Why not both?
You may think that these two mix like Oil and Fire, but the only thing getting burned here is 25% of the opponent's deck if they don't kill your Forest Guide before you copy it and start playing your giant taunts that will come back at least thrice over.
Card Draw: You don't need to add extra card draw if Forest Guide can draw you all the cards you want. Just beware of burning cards if you don't have Hadronox or both Naturalize in your hand. You can easily punish greedy Warlocks and Shamans by playing these things turn 4/5 and copying them, then sparing a naturalize to burn more cards.
Against aggro: Even if they draw every card in their deck, you can draw all your removal and taunts, so don't worry about overdoing the draw power. The armor you gain and the health you save from spamming taunts, or even playing Malfurion the Pestilent if you think you can get away with it, is enormous. Big enough to beat aggro almost every time if you cast your Swipes right and draw into early taunts, ramp, or Oaken Summons
Mulligan: Always Mulligan for Ramp and 3/4-mana cards, (minus Swipe,) and against Priest, Mulligan for Malfurion because a taunt wall will do nothing to combo priest. If you gain enough armor fast enough, you can fatigue Mind Blast Priest pretty easily. I've done it before. Against Warlock, try and go for the cheeky turn 5 mills once they've drawn a few cards and never let the pressure up from there. Sometimes you have the option to keep Forest Guide on account of increasing consistency for Oaken Summons. Handy against Paladins and Warlocks since you either DO want early guide or DO NOT want early guide, and this allows both options.
Copy Cards: Common Taunt Druid doesn't use Faceless Manipulator, (which can get you more Forest Guides, The Lich King, or whatever your opponent has,) and may have a slight edge over lategame value decks compared to this list. However, lategame value doesn't matter if you're 6+ cards deep into fatigue and at least 2 cards up on your opponent. If it mills more cards, or straight up kills your opponent, it can be worth spending the 5+ mana for more guides/taunts, or using Carnivorous Cube to power up Hadronox prior to playing it.
In my practice, this deck was more consistent than regular taunt druid. Let me know what you think of it, and I suggest trying it out and comparing to see which you like better. Have fun!