The thing is, paying two mana to draw one card a turn for a few turns looks pretty abysmal when compared to cheap draw like Secret Passage, Cutting Class, and even Swindle. Weapon Rogue just works at blinding speed right now that Silverleaf Poison is probably to slow even in a Swinetusk Shank deck.

I like your list. I've been trying to get some inspiration from other people's lists and found some here. If you want some suggestions, here's what I have to offer:

What to potentially cut:

From what it sounds like in your deck guide, you're not too sure about Shooting Star. I do think Shooting Star is the weakest card here in context as it was historically run in decks that utilized more spell damage. I also think that Yogg-Saron, Master of Fate might prevent you from getting Mordresh Fire Eye from Taelan Fordring when you need Mordresh to finish a game or clear, but if you want to run Yogg for fun, go for it. Lastly, I think Snap Freeze might prove to be too low impact and not synergize well with Glacier Racer and Varden Dawngrasp.

What to potentially include:

I do like the idea of Armor Vendor like you mention. I'd also consider including Arcanologist to help find your Ice Barriers against aggressive decks. You might consider running one Counterspell or Rigged Faire Game to help with Arcanologist's draw consistency. Lastly, I think Wand Thief would make a good inclusion as discovering spells for cheap in Mage is really efficient and can lead to more Wildfires.

When compared to Veteran Warmedic, there aren't a lot of Frost spells for Mage to take advantage of alongside Rimetongue and Mage doesn't have a way to leverage the relatively vulnerable tokens.

Just like Xaril, Poisoned Mind proved to be slow for Rogue, Apothecary Helbrim is probably doomed to the same fate. There is not much of a reason to have random extra poisons when you just need a Deadly Poison and a Nitroboost Poison on a Self-Sharpening Sword to win the game.

The issue with this and Blood Shard Bristleback is that they have anti-aggressive effects, but you can't have these effects for anti-aggression in the early game. These remind me of the omega cards from the Boomsday Project where people thought they could justify running omega cards against aggro because they were decent stats on-curve, but they ultimately proved to be inconsistent in reaching their effects.

Along with Stage Dive and Outrider's Axe, there is a pretty good draw package here to support a C'thun Control Warrior. There are a lot of situations where Stonemaul Anchorman lives to draw you a card and remove an enemy minion.

This is basically three Hammer of Wraths spread over three turns for the price of one, not to mention how insane this is to curve into Doctor Krastinov or Mor'shan Elite.

This is a pretty threatening top end finisher for Secret Paladin decks. Even just two secrets makes this a scaled up version of Dire Wolf Alpha. There is a slight downside in that you won't initially have any secrets to defend your board with (Oh My Yogg! being a critical one to combat AoE), but you will get some potential to defend it if the 3/3s are removed one by one. 

I imagine Secret Paladin will run one copy of this for the sake of having five different secrets, and since that's what's been the case historically with Rat Trap and Hidden Wisdom. There is a lot of hidden value in having a secret that isn't easily triggered to activate your secret synergies like Sunreaver Spy and Northwatch Commander.

A powerful effect to be sure, but this has severe anti-synergy with Death Speaker Blackthorn who wants you to keep Deathrattle minions in your deck. This also comes a bit too late after Razorboar and Razorfen Beastmaster as you want to draw the deathrattle minions for when they die. Honestly, I think that Vengeful Spirit has more of a chance to see play outside of Deathrattle DH in a future where there are powerful standalone deathrattles for DH or there is a combo that requires deathrattle minions.

This is the same story with Razorfen Beastmaster: there just isn't a good selection of deathrattles that allows for both Razorboar's and Beastmaster's deathrattles to be consistent enough. Also, it would feel pretty terrible to pull these two deathrattles off of Death Speaker Blackthorn and not have any deathrattles to cheat out in hand, which I imagine will be very likely given the lack of good deathrattles to run.

Most of the power from deathrattle decks comes from being able to trigger deathrattles to achieve a powerful effect that's worth more than the cost of triggering the deathrattle. Now knowing all of the DH cards for this expansion, not only are there no ways for DH to trigger deathrattles, there aren't very many great choices of deathrattle minions to cheat out with Razorfen Beastmaster. I just think Deathrattle DH is doomed to fail.

Unless you're looking for specific deathrattle minions with this, this has a pretty low power output for DH. Even in the Deathrattle DH context, this draw deathrattles that you may want to pull off of Death Speaker Blackthorn. I just don't have much hope in this archetype as the available deathrattles aren't particularly strong enough.

Druids don't care about this because they are either running Fungal Fortunes or Guardian Animals. This has more of a chance in Shaman, but I'm skeptical of a Control Shaman being as efficient as Control Warrior or Warlock.

This helps a potential Pirate Warrior curve with Bloodsail Deckhand into Fiery War Axe. I don't know if Pirate Warrior will have enough consistent tools to see play, but Ratchet Privateer certainly helps.

I'm getting some scary Ramp Paladin vibes off of this. The fact that the opponent will have less to do than you and Celestial Alignment allows you to get Druid of the Plains off of Guardian Animals, this allows for some non-interactive blowout games from one card.

Token DH needs more consistent payoffs to make the archetype work, not more token summoners. Vile Call is possibly the worst token summoner as, without rush, you can't easily take advantage of payoffs like Feast of Souls. If you want this for the lifesteal, DH has plenty of other more efficient early lifesteal options than this.

This is worse than the OG Grim Patron as you can't get two Gruntled Patrons from one of them, so it lacks the scalability. Also, the tools that made Grim Patron good back in the day, namely Warsong Commander, do not exist in the same way today, meaning the Gruntled Patron doesn't really have a payoff.

This is scary considering that this can enter play on turn three while you have two secrets thanks to Sword of the Fallen. Quite a few paladin secrets, such as Noble Sacrifice and Oh My Yogg! can protect Crossroads Gossiper and scale it up into a threat at the same time. You only need one secret to trigger for this to become efficient, although I don't see this much anywhere else outside of Paladin.

The stat line isn't aggressive enough and the effect isn't consistent enough to see play in Murloc Shaman, not to mention how this is competing against other, more aggressive two-drops like Lushwater Murcenary and South Coast Chieftain at the two-mana slot.