I run the Wildfire Archetype in my Cube. It contains both
wildfire and
burning of Xinye. The Wildfire archetype is an interesting one, and often includes mana rocks just as much planeswalkers, as a way of keeping your lead. Signets/etc. are all excellent in Wildifre as 'mana dorks' that don't die to your own wrath effect.
In power-max cubes (such as mine), Wildfire decks will tend to stay away from Green, and move towards white if they can, in the hopes of picking up [[balance]], which also happens to synergize incredibly well with both mana rocks and planeswalkers.
[[garruk wildspeaker]] and co. do not help you recover as well as you think they do. Well... it's less that, and more that if you've drafted a proper Wildfire deck, you won't need them due to mana rocks. I will say that [[chandra, torch of defiance]] is very good for the archetype, although the inability to play lands from her first ability tampers it somewhat. Imo, the best planeswalker currently for the archetype is the recently printed [[nahiri, the harbinger]] as she provides card selection to get you out of the screw, and a shockingly fast clock on an empty board. She also happens to be in [[balance]] colors, which is another bonus.
Bringing out Wildfire early isn't something that is going to happen very often. You typically want to wait until you can hit a maximum threshold of value on your wildfire/burning, so ramping it early isn't really all that valuable if you're doing it to mutually destroy lands.
If you're doing it because your opponent's boardstate has gotten ridiculous and you need a wrath, I imagine your Chandra won't survive a turn to help with that...