I run Cabal Coffers because of it's synergy with Prismatic Omen and to piggyback on opponents' Urborg, Tomb of Yawgmoth s. I have far more enchantment protection than land protection and Prismatic Omen also doubles as a Valakut, the Molten Pinnacle and Emeria, The Sky Ruin enabler.
This deck looks like a lot of fun. I do not know if it will be all that effective but I like the fact that you can have so many different things going on at once.
I see you took the expensive route at a mana base. For me I would have built it to be primarily G/B so I can ramp and tutor into all the combos.
+1 from me
If you add a copy of Training Grounds, there's an infinite combo with the Gilder Bairn and Paradise Mantle.
I'm aware. I'm not too interested in going infinite; it makes it simply too easy.
How about Inexorable Tide for amazing proliferation with your walkers.
Also Diabolic Revelation is a game ender. I'd definitely consider putting it in as well.
I tried out Inexorable Tide during the early testing, but I never wanted to actually cast the enchantment. Even if I did, it would never happen more than twice each turn, so I elected to go with Contagion Engine instead.
I'm trying really hard to shy away from Tutor -> Win. I do it in too many decks as it is.