I think that it can be decent in the deck but the "Overrun" isn't as good here as the deck doesn't run that many creatures (like "Green Devotion" for instance) usually and the finishers (Stormbreath.D, Inferno.T) are pretty big anyway and close games fast without any help.
Chandra, ToD provides ramp as well and has much better utility as removal+CA so she is generally preferred in this deck.
I don't think that a an anti-flying wrath effect is good enough for the maindeck (or even the SB) for this deck, hence why Hurricane/Squall Line (which also hits players) or Windstorm isn't played.
Another card that can be good here (if you can resolve it) is Trinisphere which can severly tax them (making Snapcaster Mage barely playable) and make them play inefficiently.
I'm not sure about 20x lands in this deck, when I started playing I was also on 20x lands but had to mulligan so much (drawing 1x-landers) so I moved to 21x.
I don't think that having 4x Courser of Kruphix would actually help the deck close games as they are a pretty slow clock. Tireless Tracker is more vulnerable (to bolt) but can grow to become a much bigger threat and can also draw cards.
The idea is to keep them under 3 lands being unable to cast anything, I admit that it doesn't always work so I'll probably get some Blood Moons as they're going be reprinted in MM3. Blood Moon can be played around and some decks don't care about it but making every (1-2cmc) spell cost 3 mana can be problematic for many decks.
Running other finishers instead of Inferno Titan seems less effective as it closes games really fast and also helps clear the board of small creatures to stabilize (which is very useful as the maindeck doesn't include actual removal).
Chandra, ToD provides ramp as well and has much better utility as removal+CA so she is generally preferred in this deck.
Against "Affinity" there are better options like Vandalblast/Shattering Spree/Shatterstorm/Creeping Corrosion or even Fracturing Gust for instant speed.
Kozilek's Return has the added benefit of hitting Etched Champion (and most Affinity creatures don't have toughness higher than 2 anyway).
I don't think that Bonfire is a good card at all, it's too much luck dependant and underwhelming for the non-miracle cost.
It should be good against anything (except for "Dredge" I guess) as long as you keep them under 3 lands with your LD spells.
Relic of Progenitus to clear the GY is also good.
You can bring in Defense Grid if you want.
Oblivion Sower doesn't do much and is worse than Inferno Titan.
Creeping Mold is much worse than Beast Within (and Acidic Slime).
Chandra, the Firebrand isn't even the 3rd best Chandra.
Fulminator Mage isn't particularly necessary with Blood Moon and Molten Rain would be better in this deck imho.
Destructor Dragon is just bad, Sylvan Primordial (or even Deus of Calamity) is much better and isn't played.
I don't think that having 4x Courser of Kruphix would actually help the deck close games as they are a pretty slow clock.
Tireless Tracker is more vulnerable (to bolt) but can grow to become a much bigger threat and can also draw cards.
(like Obstinate Baloth, Thrun, the Last Troll, Polukranos, World Eater, Chameleon Colossus, Pia and Kiran Nalaar, Huntmaster of the Fells).
Smoldering Werewolf is not a good creature.
Blood Moon can be played around and some decks don't care about it but making every (1-2cmc) spell cost 3 mana can be problematic for many decks.
Running other finishers instead of Inferno Titan seems less effective as it closes games really fast and also helps clear the board of small creatures to stabilize (which is very useful as the maindeck doesn't include actual removal).
Btw, GR Ponza finished 9th in the recent tournament:
https://www.mtggoldfish.com/deck/592463
It uses the "Madcap Emperion" combo (which I'm not a fan off here) and 4x Banefire for some reason (maybe it's a typo and it should be Bonfire of the Damned).
I'm not sure if Thragtusk is worth it over the 2nd Stormbreath Dragon (better finisher) or the 3rd Obstinate Baloth (doesn't trade with 3/3's).
And there are also: Huntmaster of the Fells, Pia and Kiran Nalaar and Thrun, the Last Troll, Chameleon Colossus, Polukranos, World Eater which might be decent as well.
I still like the idea of running Goblin Dark-Dwellers together with both Stone Rain and Molten Rain to flashback them (and Beast Within).
I also don't have Blood Moon and run Trinisphere instead.
4x Arbor Elf
2x Birds of Paradise
3x Obstinate Baloth
4x Goblin Dark-Dwellers
4x Inferno Titan
Enchantment (4)
4x Utopia Sprawl
Sorcery (11)
4x Stone Rain
4x Molten Rain
3x Mwonvuli Acid-Moss
3x Beast Within
Artifact (3)
3x Trinisphere
Planeswalker (1)
1x Nissa, Vital Force
Land (21)
4x Wooded Foothills
4x Windswept Heath
4x Stomping Ground
1x Kessig Wolf Run
6x Forest
2x Mountain
3x Anger of the Gods
1x Beast Within
2x Destructive Revelry
4x Lightning Bolt
1x Mizzium Mortars
1x Obstinate Baloth
1x Pulse of Murasa
2x Scavenging Ooze