Hearthpwn

Harvest Golem is too weak in powerlevel, which this deck needs to be as fast and as powerful as possible. I realize Harvest is durable, but that is not what this deck is seeking.

In your case:

-1 Dr Boom
+1 Pyroblast

-1 Loatheb
+1 Polymorph (if more control decks) or Water Elemental (if more Weapon Decks)

Hopefully this helps! Good luck and grind on,

-WIngs

Both Mage and Shaman have their merits to them.

Typically the Mage version seems better as the Aggressor, with a Hero Power and Efficient Burn spells to back it up. I would say the Mage version is better in a more Aggressive field, but Shaman also could potentially have Lightning Storms to help out in this scenario, so it goes back and fourth. However you are forced to build your deck aggressive with a Mage because of the design of Jaina. 

The Shaman version is a little more sturdy with it's own set of powerful mech cards - Powermace & Whirling Zap-o-Matic. Powermace is the strongest of all because it allows you to eat early minions to preserve your own Mechs on the board, which then eventually get buffed after Powermace has been used up. Whirling Zap-o-Matic doesn't usually stay on the board, but when he does it is an insane amount of damage. I feel this strategy is better against Control and Midrange formats, but both are viable options. 

At the end of the day they are extremely similar and it comes down to personal preference. I would say the Mage is more consistent, but that's not to say the Shaman isn't consistent (because it is). Archmage Antonidas is the reason I tend to lean towards Mage, because it gives you a card that can turn around a game quickly or defeat specific Heroes like Druid by keeping it in your opening hand. 

Hopefully this sheds some light on the subject.

Good luck and grind on,

-Wings

One of the Tinkertown Technicians are a slot you can play with so if your running into a lot of Aggro, I would cut one of these for an AOE spell.

Glad you've been enjoying!

Good luck and grind on,

-Wings

Enhance-o seems like an interesting fit. If he's working out for your then keep him in! I'm not a huge fan of the RNG he has, but when it works in your favor can definitely win games.

Good luck and grind on,

-Wings

I would put your next priority to craft as Dr Boom. He's such a powerful card and fits into so many decks. For now a Sylvanas or Sky Golem would work just fine. Also, thank you for the follow on Twitter! ^^

Good luck and grind on,

-Wings

Thank you very much for the kind words and I'm glad you found the guides helpful!

Duplicate doesn't have the same impact as Mirror Entity in this deck. The Entity lets you stay on par with your opponents minion and is more of a Tempo Play. The Duplicate is mostly there for Midrange and Control decks to gain a source of card advantage. There are a lot of pretty mediocre minions you can create copies with from Duplicate from Mech Mage, so I don't find it very helpful because of this.

The Mirror Entity is stronger because it effects the board right away. Which is what this deck is looking to accomplish. 

Your decklist is very similar to mine, I would just consider swapping the Duplicates for Mirror Entities or 1x Mirror Entity & 1x Counterspell. This should help the deck smooth out even more in the long run.

Hopefully you found this helpful! Good luck and grind on,

-Wings

I would sub out the Sky Golem for a Flamestrike. 

Good luck and grind on,

-Wings

Emperor Thaurissan is not a great card in this deck because there's no Draw Engine to keep your hand full enough to get value. Force-Tanks is also pretty underwhelming. I would just built the budget list and add Antonidas to it.

http://www.hearthpwn.com/decks/272893-budget-mech-mage-legend-grinder-guide

-1 Flamecannon or -1 Ironbeak Owl for the +1 Archmage Antonidas

Hope this helps! Good luck and grind on,

-Wings

Not a problem! Glad you found the decklists helpful!

Either would be a decent replacement. I kind of like the Ragnaros more since it stays with the Aggressive theme. 

Good luck and grind on,

-Wings