It's a bad idea to run 1-of Guildgates in case something happens to them.

Unless you run Crucible of Worlds .

so, the real issue with running more than 1 of some gates is that you end up with colors you don't need. An opening hand of 2 izzet gates and 1 rakdos gate is an instant mulligan.

Pretty much the approach to land destruction is: either they are playing land destruction or they aren't. If they just have ghost quarter then first they have to destroy 1 of the 5 unique gates. if they manage that then you have to fall back on the elixir to win the game.

If they are playing real land destruction (deathrite shaman, acidic slime, nicol bolas, etc) then you fall back on the crackling perimeter win.

I would think there's a better alternate win condition when they sowing salt you, what do you do when the mazes end is sowing salted? Also, bu bu can't search libraries draw a card is another of your issues. Do you find if they blow yp azusa or your amulet of vigor? Single ghost quarter pwns too if Iknow which is a singleton, but you seemed to have thought of that. Other than that, its stupid, and needs a better name.

so, no one plays Sowing Salt cause its crap against anyone but this deck, so I'm not too worried about that. If they play something like Aven Mindcensor then he'll just get Terminus 'ed. I did find that Azusa, Lost but Seeking pretty much died the second she came into play so she got replaced with Summer Bloom . And if you lose an Amulet of Vigor its not that big of a deal. You can usually find another.

Summer Bloom is definitely superior, but Sowing Salt is a staple because of its use against TRON (along with shadow of doubt/ aven mindcensor). I hope mindcensor is a staple because other than taxes I can't explain why the card is around $10.

Notes: How about a Primeval Titanand a Perilous Vault?

I didn't include prime time cause the earliest you would get to use him is around turn 6 - 7. he would get you two gates but you'd probably have to board wipe him away and never get to attack to get two more lands. having a prime time sitting in your hand for six turns is just bad, especially when you wish you had a fog.

In some situations perilous vault may be better than planar cleansing, but theres a lot of artifact hate out there. May just have to playtest it and see what happens. thanks for the comments!