Chandra, Torch of Defiance - Oops! All Chandras.
Prime Speaker Zegana - Draw for Power.
Pir & Toothy - Counterpalooza.
Arcades, the Strategist - Another Brick in the Wall.
Zacama, Primal Calamity - Calamity of Double Mana.
Edgar Markov - Vampires Don't Die.
Child of Alara - Dreamcrusher.
Great. Now the people on Ravnica will hate Vraska even more!
Depends on what "cooperation" means, most of the guilds would never give up autonomy in order to work with others- only three of the white aligned guilds would see it as a virtue (Boros, Azorious, and Selesnya), so it could be that the assassination would be lauded rather than hated.
So it seems Gates are the UG Draft Archetype of GRN. Obviously things will change in the next set once we get the Simic, but right now, seems fun.
Cantripping out of lands is a pretty great effect - compare it to a Seer's Sundial that requires U. The fact that it also gives you value if played lategame is also quite strong for the decks that want this kind of effect. Honestly, I wouldn't be surprised if this card saw some Control playability in Standard.
As for District Guide... it's meh. I'd rather use Gatecreeper Vine.
Guild summit is great. Every two-colors lands enter the battlefield tapped but grant you a card. Theros scry land got heavily played, cycle lands get played and they also both always came into play tapped. Granted, now you need that enchantment to turn it on and at 3 CMC, it's probably too slow and too late, but free cards off playing lands is nothing to scoff at.
And wow!, it's not a dead enchantment in multiple. It even gets quite a bit crazy to raw multiple cards off each gates played. If the original karoos in Ravnica got played, this certainly has potential.