Now of course I see that “secret” is in the deck title. Anyway, the point still stands that this has the bones of a very good odd mage deck and you can play around with it to make it very good!

This deck is excellent. I too dropped the Nightblades for two Faceless Manipulators and I have found that to be a welcome level of added flexibility (remember that they can also copy opponent’s minions). If you manage to get them to copy your Clockwork Automations then your hero power will win you the game). You can also use them to summon copies of Ragnaros which is quite fun. I also threw an extra counterspell in there for the Funglemancer since I was never using it, and dropped a Dire Mole for a Cobolt Scalebane.
Two things to consider when making/improving this deck:
1) the secrets strategy is somewhat underwhelming. Secretkeeper + Kirin Tor Mage + Counterspell/Explosive Ruins is ok, but frankly I think that replacing these cards with taunt cards to protect your two other winning conditions (Clockwork Automations + hero power / Ragnaros) would be something to explore. I haven’t tried it yet but I think it would make the deck a bit more stable and less reliant on the luck of drawing the appropriate cards for this combo.
2) this deck is TERRIBLE (and I mean TERRIBLE) against token and control decks. Odd Paladin kicks this deck up and down the board. I would potentially consider including an AoE remover (e.g. Flamestrike) because a) I never struggle to survive until turn seven anyway and b) once your opponent has that much on the board, your win conditions go out the window (they will either destroy your Clockworks or Ragnaros’s ability will have too much to target… plus he will get killed the next turn).
Just my thoughts. I’ve really enjoyed playing this deck and it’s working great for laddering but those are the pitfalls that I’ve noticed thus far.

I’ve been rocking this great deck with a Spirit of the Shark, Cursed Castaway, and Captain Hooktusk. The combo of Spirit of the Shark + Elven Minstrel + Shadowstep is insanely OP.
I’ve had several games where I played Spirit of the Shark on turn 4, and on turn 5 played coin, elven minstrel, shadowstepped him back, and then played him again and drew 8 minions. You can clean up really easily this way and I highly recommend including at least Spirit of the Shark in your deck.
Cursed Casaway and Captain Hooktusk are solid late-game cards, though honestly I’ve never needed them. They are nice insurance but generally I’ve already won by turn 6-ish.