I brewed with a lot of other decks over the last year, but Arianrhod this Sneaky Build is bonkers and may help that i grap my dust-covered Nic Fit cards again. Great idea - thank you!
I also like (since i played Punishing Fit alot) Bobmans idea with PFire: repeatable Removal Spells aren't not the worst idea (look at DtB, a lot of decks with creatures), it also improves the already strong Primeval Titan.
Overall i am not sold on the full playset (especially not if you have also the PFire Engine) of
Sneak Attack and would like to see a 3:1 solution, with either a single tutor like
Diabolic Intent or a cc4 planeswalker like
Garruk Relentless (kills a dude, stalls the field and can also tutor up bombs once flipped).
I would also vote for at least 2
Carpet of Flowers at Side, it's perfect since we already cut Explorers vs Miracle and it will help against all the tax counters (paired with Wastelands) if we play against delver decks.
@Arianrhod: I feel thanks to PFire Engine the miracle matchups improves also one step, even more with carpets. I think exclusive cards like Ugin, the Spirit Dragon, Gaze of Granite aren't needed with this Engine or other maindeck improvements. I personally would grap Garruk Relentless over any Ugin in terms of speed (cc4 vs 8) and matchups because you can use Garruk against various decks compared to Ugin that feels like he is only for "Drop a nuclear bomb vs Miracle". Gaze of Granite is more or less the same, since you need 5+ mana in most cases you can also pack other a lot of other cards but overall i think you don't need more bombs if you already include the solid PFire Engine in terms of manasink or grind.
Some cards i like to discuss with all of you:
Kolaghan's Command: very flexible, always 2:1, it is not as dead as other removal spells if you have nothing to kill on the field and can also grap creatures for another round with Sneak Attack
Karakas: As land number 23 (with 61 cards), it will slightly improve hard matchups like reanimator, sneak show, lands (Primeval Titan can also find it), can EoT bounce Gaddock Teeg or taxing Thalia 1.0 if we wan't to slam down Sneak Attack or cast Zenith - Karakas can also be solid if we see a rise of DnT (especially if they also run Thalia 2.0) and you can bounce your own Grisel&Emrakul after Sneak. Maybe it needs legends like Sidisi, Undead Vizier, Nissa, Vastwood Seer or Tasigur.
Nahiri, the Harbinger Hell's Kitchen because you need W but this seems to be the perfect planeswalker, cc4, can cycle useless cards (synergy with PFire), a fast and perfect ultimate and on top can also kill some stuff if needed. It is possible to squeeze in 1-2 copies of her into the deck (for example cut Sidisi, and use only 3 Sneak Attack).