Here's the updated list. I'm going to annotate exactly why I use each card more clearly.
1x Bloodmage Thalnos
1x Wild Pyromancer
1x Healing Touch
1x Tinkmaster Overspark
2x Keeper of the Grove
2x Druid of the Claw
2x Gadgetzan Auctioneer
1x Sylvanas Windrunner
1x Ancient of War
1x Ragnaros the Firelord
This is fairly obvious. It combos with Gadgetzan & provides quick early plays. On the seventh turn, I've often played something like Gadgetzan Auctioneer + Innervate + swipe or bite. This equals two card draws, plus good removal, and a 4/4 body enters the field. In the worst-case scenario, this card is sometimes played in order to activate the hero power after dropping a 9-drop on the field (if the game is playing out a long time & Innervate is drawn late).
The way this card is played is not obvious, and it's not straight-forward. Moonfire synergizes primarily with Malygos and Gadgetzan Auctioneer, however on very rare occasions Bloodmage Thalnos is relevant as well (usually not on the same turn moonfire is played though, so usually it's just Malygos or Gadgetzan). However, Moonfire isn't necessarily a combo-only card; if I'm being rushed down, or need to output an extra 1 damage, I gauge the scenario and decide intelligently whether it's worth playing. This takes a fair bit of experience and thought. The moonfires are a core piece to this deck, and are necessary for this deck to function.
Claw is one of the best 1-cost spells in the game. The primary use for claw is for early-game removal. The secondary use is for mid-game draws with Gadgetzan. The tertiary use is simply to output damage and/or gain armor (possibly defensive) at later parts of the game. The card is relevant at all points during a match. I often play claw in anticipation of a high damage-output turn from a warlock; the play sometimes appears as though I've wasted the card, however the two armor gained makes the difference between a win & a loss quite often.
Wrath essentially serves the same purpose as claw, but offers some utility. If I'm in late game, I opt to use claw & wrath (if possible) before I use swipe. Any spell damage which I can direct to either creatures or a player is valued higher at late game.
This card is in the deck because it works well alongside wrath (allowing for 2 damage & draw a card, or 4 damage -- both very relevant), and also works amazingly well with swipe and starfall. In a worst-case scenario (or if you're simply finishing the opponent off), dropping Bloodmage Thalnos with no follow-up spells is occasionally the correct play.
A new addition, and it makes sense. As discussed above, Wild Pyromancer is very effective against early aggression. I think this will make for an extremely relevant addition to the deck, and will make moonfire even more of an interesting card.
One is absolutely paramount to the deck's success. Without healing touch, this deck's mid game is statistically worse against aggro decks, and the deck's late game is significantly worse against control & mage decks.
100% necessary. Deals with Sylvanas, Ragnaros, Ysera, and so on. Besides the obvious plays, I'll provide an example: My opponent has a 2/2 and a 5/10 in play. I have very low life. I have Sylvanas, Ancient of War, Starfall, and Tinkmaster Overspark in hand. I have 10 mana. My opponent has 1 card in hand. I play Tinkmaster Overspark first, and his 5/10 becomes a 1/1. I then activate my hero ability, kill his 1/1, and play my Sylvanas. If the 5/10 became a 5/5, I would have played starfall on the 5/5, and activated my hero ability instead. Tinkmaster Overspark allows for interesting play options, and enhances the effectiveness of the way a hand can be played out. Furthermore, Tinkmaster Overspark can act as an early-game flip card: If my opponent has a creature that I value similarly to a 5/5, and the aggression is heavy, Tinkmaster Overspark is occasionally the correct play.
Keeper of the Grove
I originally considered this to be a dead card in the deck due to the way the deck plays. I ran this as an automatic 2-of in any other regular druid deck I have, however it was an oversight for me to not play this card in the deck. Keeper of the Grove offers early & mid game defence/removal, and late game neutralization of threats. A necessary card in the deck.
Completely necessary, and one of the core cards in the deck. This is a dual-purpose card. Usually bite is used as removal. Bite is often used as direct-damage, but not quite as much as removal. Finally, Bite serves as a 4-armor generating card without being focussed like healing touch is. Without Bite, this deck would absolutely fail.
I don't think much has to be said. It's an excellent card. Like every other card, swipe is used as removal more than it is used for direct damage. Swipe is a card which much be played very carefully (just like starfall). I take into consideration the life totals & divine shield states of everything in play. If I can't remove everything I want from the board, I take into consideration what I can follow up with on the next turn, and how to play swipe as best as possible in order to do that. Sometimes swiping the player's life & following up with a larger hit to my own life (using the hero ability to finish off a minion that had 2 life, for example) is the better play in order to put greater aggression on the opponent's life. It all depends.
Always prioritize using starfall over swipe if at all possible. Swipe can be used as direct damage to the opponent. Starfall can be used to sacrifice Sylvanas... this play isn't all too uncommon (maybe one in 20 games or even more frequent).
Druid of the Claw
It's a big defensive creature. Don't be afraid to use charge: At higher more competitive levels of play, silence & creature pumping is a thing. If you can charge down a 2 or 3 attack creature, your druid of the claw will still be alive & will have to be dealt with. If you set up a 4/6 static creature on the board, your opponent can choose how he deals with it. Either play could be correct, but I make Druid of the Claw into a 4/4 more often than anyone else I know.
I feel like this card is at the heart of the deck. When he enters the field, things happen. He doesn't always have to do something significant, but more often than not (more than 50% of the time most certainly) I draw at least 4 cards off of a single Gadgetzan Auctioneer. I will often gauge situations as well: if I have a moonfire in hand & my hand is dry, I sometimes use the moonfire (even if there isn't a desirable target) in order to shift through my deck (since you cannot rely on Auctioneer lasting to the next turn, though he usually does last more than a turn if you're playing a good game). If I could, I'd only run one in the deck if I were guaranteed to draw Auctioneer within the first 4 draws... the reason I run 2 isn't to be able to play 2, but to draw into Auctioneer in most of the games I play. With that said, playing 2 in a given game isn't a bad thing: he's still a 4/4, and I find they get removed so a follow-up Auctioneer is by no means bad.
I've tried removing Sylvanas for cards such as Naturalize. Sylvanas is too good to remove. She offers similar levels of advantage as Ysera, Ragnaros, and Malygos if played correctly. She is also a utility card, since she can simply be laid out to generate pressure but not offer as much recurring advantage as the aforementioned legendaries.
Ancient of War
Always play this as a 5/10, never as a 10/5 ever. It's a big wall. Sometimes it's not the correct play when you need to play defensively... often times it is though. It's great as a 1-of in this deck, rarely do I want 2 in the deck though.
Ragnaros the Firelord
This card can be clunky occasionally, but overall he fits into the deck very well. He's recurring damage, removal, and often defensive. I usually expect him to be removed, and I don't expect him to be a sole win con in any given game. The reason why I have Ragnaros, Ysera, Malygos, and Alexstrasza in the deck is to provide enough win con material to take on any deck. Paladin control decks, druid defensive decks, priest decks, etc... there are many decks which dry out all of your win cons & deal with you. I've tweaked this deck to be able to deal with every type of deck there is. I haven't added this many large creatures simply for fun... although it is fun :)
Both offensive and defensive. I very rarely drop Alexstrasza on the board with nothing else there simply to set my opponent's life to 15. This card really adds play to the deck, and is essential against some very prominent high-tier decks. Alexstrasza has won me games more than enough times (usually as a defensive card).
Usually Malygos drops down & gets silenced, transformed, or killed. I often only get one 6-damage moonfire off. However, as a silenced 4/12 body, Malygos is effective. If he lasts more than a turn & I have spell damage in hand, it's game over 9 times out of 10. Malygos is essential to this deck & removing him would cripple the deck's competitive edge in many matchups.
You start drawing from a whole new deck with Ysera on the field. This card provides value. Sometimes it's difficult deciding when to place Ysera on the board, but that's about it... Ysera is necessary in this deck. As I mentioned under my Ragnaros explanation, Ysera provides additional win con material beyond the basic face-value damage of spells & minor creatures.
Don't be afraid to use the hero ability to attack a 3/2 in order to get a better swipe off the next turn. These sorts of plays are really dependent on a lot of variables. If you use your hero ability on a 3/2, and your opponent Defender of Arguses on it, you're in for some hurting (as an example). The druid's hero power is important & how you decide to allocate (or not allocate) the damage and take advantage of the armor gained (or mitigate the damage you take as a result of attacking) contributes to game wins or losses.