Hearthpwn

It's actually very easy to get into Wild, unless you want to go for something very set-synergistic like Mech Mage. It's usually possible to find many Wild decks that are simply Standard decks with just a few Wild cards, just because the game inevitably power creeps over time, making each Standard cycle more powerful than the last. You will for example find Jade Druid, Renolock, Pirate Warrior, Aggro Shaman, Miracle Rogue, Anyfin Paladin and Freeze Mage in Wild. When I played last season (EU), the most popular deck overall was Aggro Shaman with the only Wild card in the deck being Crackle.

Additionally there are WIld staples that always will remain powerful, such as the soon-to-rotate Azure Drake, Reno Jackson and Brann Bronzebeard. The best deck in Wild might change over time, but the powerhouse cards will mostly remain the same, so it's a cheaper format to keep up with compared to Standard.

That said, if you're a new player and you have to choose between Standard and Wild, Standard is the obvious choice since it's significantly better to open a card from a pack (or Adventure in some cases) than having to craft it. Getting your first viable deck would take much longer if you went directly for WIld.

I'm in favor of bringing back Wild packs (and Adventures). That would solve most of the disparity, but not all. There is still the problem of Tavern Brawl, quests and Arena awarding only Standard packs. It would be really cool if they simply duplicated the number of rewards and gave everyone the normal Standard pack + an additional Wild pack, don't force people to choose between the modes, promote both at once. Though to prevent people from just getting double dust they would have to make a separate Wild dust type that Wild cards disenchant into, that can only be used to craft Wild cards.

I think it's important that cards still come primarily from packs, not from crafting, since the discovery and experimentation that comes from pack RNG is very core to CCGs. Crafting should only be used to fill gaps, not to build the core of the deck.

There are three core issues with secrets.
1. Most secrets have poor tempo and value when played early on. Late in the game they're usually pretty good, but not good enough to compensate. The most notable weakness is how bad every single secret is against minion-based aggro decks.
2. Many secrets are unreliable, in more ways than one. If you play a Mirror Entity you count on them playing a minion worth copying. If you play a Counterspell you count on them playing a spell worth countering (or a spell at all). Additionally a big part of the secret power budget lies in your opponent not knowing what the secret is, but that is not usually the case in practice. Finally there are many minions that rely on you having a secret up when they are played, those are generally very unreliable unless combined with exactly Ice Block, and Ice Block is a bad card for a tempo-based Secret Mage.
3. Secret-synergy cards are not good enough to compensate for the price of running the actual secrets. Consider what it took for Paladin secrets to see any play, Mysterious Challenger, one of the most broken cards in the game, and that's with Paladin secrets actually being quite good tempo for their cost. What's the best secret synergy Mage has? Medivh's Valet? That's not enough to carry a deck.

I think that what Secret Mage needs is first of all a secret that's not strictly for control like Ice Block, but that is similar in that you can expect it to stay up until the next turn. Currently there is Effigy, but I think there needs to be at least one more for better consistency, especially since Effigy is weak to Hex, Polymorph, and any aggro deck that just goes face anyway (and it's not particularly good when triggered by a 4-drop). Secondly there needs to be a 4-drop with great secret synergy, to catch up with the tempo you lose from preparing a secret on turn 3.

The constructed polls in general are quite pointless since the vast majority of the cards will be judged without seeing which synergies will exist (or how the meta will turn out). Just as an example, I rated the Hunter 3/5 that grabs two 1-drops as mediocre regardless of deck, but with the quest revealed it suddenly got way better. The poll is just a bit of fun.

An Arena poll actually does make sense, it's a relatively stable meta where synergies matter a lot less, so you can make quite accurate predictions.

You also need a solution for getting rid of a taunt that's in the way.

Easy quest, strong reward, should be good!

The new 1-drop elemental is going to be absolutely insane for this deck.

I think the only deck that will use this card is some version of wild Secret Paladin, 

Hmm, I think you need a solid stall effect to play along with this. You can use this and play nothing, but then you potentially take a ton of damage, and your opponent will maintain board control. You can use this and play a taunt, but then the opponent will just sacrifice everything into the taunt (and your face) and still maintain board control. If only Warlock had Frost Nova.

A 1-of in every N'Zoth Priest. Two might be a little too much since it can be difficult finding a target early on.

Good in arena, needs much more synergy for constructed.

The worst card announced so far, Jesus... You play this, they play a taunt, you sacrifice all your treants to kill the taunt but still have only 1 mana because the deathrattle gives empty mana crystals. If they don't have a taunt they can wipe the board with AoE.

And then there's Devolve, Potion of Madness, MCT, etc.

Superb control card, but I've still haven't seen enough Rogue cards to support a control playstyle.

Very interesting with spell synergy. Archmage Antonidas in particular loves cards like this, but there needs to be more cards like him for this to see any play. It has a good chance of getting a 1-2 cost spell, most decks run those, which is really bad value-wise, so you need to be able to take serious advantage of the fact that the spell will costs 0.

I think I'd rather just run Acidic or Harrison in most situations. This card is better against specifically Pirate Warrior, but worse against every other deck because of the poor stats. Pirate Warrior will die off anyway from all of the great taunts coming up.

Exception: Control Warrior, just because you can use the armor for Shield Slam.

Yeah, Aya in particular has no replacement. There's no way to make a Jade deck without her :/

Excellent design! Guessing which card is correct should be super easy by turn 3, but the mechanic is still a very fun spin on what would normally just be a boring thoughtsteal effect. The time it takes to choose a card can also be an indicator for your opponent as to what you might have got. For example if you are playing against Control Warrior and see Shield Block, then that's an easy choice, but what if your choices were Harrison Jones vs. Ysera? From you taking a longer time to choose, your opponent could guess that you just got a card that is not in every Control Warrior deck.

Power level wise it's good but not amazing. Against many decks you run a high risk of getting fairly useless cards, as has always been the case with Thoughtsteal, and it doesn't have deathrattle so it will probably not be preferred by N'Zoth Priest over Shifting Shade. Decks that normally would have run Thoughtsteal will probably pick this instead though, since it's a better compromise between tempo and value.