Looks good! With ~30 nonland slots left, I'd add the following stuff:

- At least three more Ramp cards: Your commander is 5 mana and might get nuked a lot due to his offensive presence. I'd add in at least two more cheaper ramp cards (such as Farseek, Fellwar Stone, Utopia Sprawl, Mind Stone, Wood Elves, Wayfarer's Bauble, Skyshroud Claim, Tempt with Discovery, or budget allowing Mana Vault and Mana Crypt) and at least one more "big mana booster" like Mirari's Wake, Zendikar Resurgent, Heartbeat of Spring, or Growing Rites of Itlimoc)

- At least twelve "Army in a Can" cards: Gahiji is at his best when you can quickly flood the board with an army "out of nowhere". I'd add at least 9 cards that can do this - some of the best cards for the job include Hornet Queen, Avenger of Zendikar, Secure the Wastes, Decree of Justice, Myr Battlesphere, Tempt with Vengeance, Sylvan Offering, Benevolent Offering, Increasing Devotion, and Martial Coup. Stuff that incrementally generates lots of tokens works too, like Legion's Landing, Rhys the Redeemed, Assemble the Legion, Dragonlair Spider, Kazuul, Tyrant of the Cliffs, Hero of Bladehold, Awakening Zone, Elspeth, Sun's Champion, Nissa, Voice of Zendikar, and Tendershoot Dryad. In fact, incremental tokens are almost better given your pillowfort-y nature.

- At least five more "answers": You ideally want your answers to be attached to creatures so Acidic Slime, Selesnya Charm, Reclamation Sage, Terastodon, Angel of Sanctions, Aura Mutation, and Artifact Mutation are all worth a look but you could also just run staples like Council's Judgment, Chaos Warp, Return to Dust, Beast Within, and Grasp of Fate. Mercy Killing and Aura Shards are interesting effects given your commander.

- At least three more "payoff"/haymaker/win-cons for all these tokens. Gahiji is his own payoff but more payoff doesn't hurt - Craterhoof Behemoth, Beastmaster Ascension, Mirror Entity, Cathar's Crusade, Purphoros, God of the Forge, Garruk Wildspeaker, Champion of Lambholt, Warmonger Hellkite, and Triumph of the Horde will all help you mop up and close out a game.

- At least three ways to "reload" - Skullclamp, Mouth // Feed, Mentor of the Meek, Shamanic Revelation, Fecundity, newcomer Camaraderie.

- At least one more cards to protect or recover you, your commander, or your permanents - Eternal Witness, Rootborn Defenses, Teferi's Protection, Arachnogenesis, Crawlspace, Sphere of Safety, Lightning Greaves, Boros Charm, Spike Weaver.

- One or two more more "goldfish" cards or cards that cause some anarchy - I'm thinking Forgotten Ancient, Hunted Dragon, stuff like that.

- If you run enough, or enough powerful, token makers it's worth considering Anointed Procession, Doubling Season, and Primal Vigor.

I like all your current card choices, so its mostly a matter of finding the right additional cards!

Thank you very much for your input! Your help with this deck has been invaluable thus far!
In this reply I am responding to most of your card suggestions, mentioning other interesting cards I have seen, and questions about certain cards.

Ramp
I like Farseek as it fixes color as well as ramp you and Skyshroud Claim as it discounts itself by bringing in lands untapped.

As for mana doublers I am leaning towards Mirari's Wake due to its cheaper cost. However, Zendikar Resurgent offers good card draw which is a little hard to come by in these colors.

Token Generation
Both Tempt with Vengeance and Sylvan Offering are going to be added to the deck. This is mainly due to the fact that they are both very economical and fit the theme of the deck by encouraging combat between the entire table. Secure the Wastes is similarly great as it helps to widen your board to profit more from Gahiji's +2/+0 ability.

I really like Awakening Zone as it makes chump blockers (or decent attackers w/ Gahiji) that are flexible due to their sacrifice ability. However, I am having a tough time imagining how this card would play out and impact the game as I've never seen it used in person.

I have never heard of Hornet Queen but I will add her right away! She is perfect as she goes wide, has evasion, and can dissuade opponents from attacking you. Kazuul, Tyrant of the Cliffs is also going to be added as he is a solid pillow fort creature.

Instead of Hunted Dragon I am looking more towards Hunted Troll for causing some anarchy. This is mainly because I think first strike is a little too good to just give my opponent, also the regenerate is pretty nice. Still am unsure about adding this type of card though.

Another card to try and spread chaos with could be Rite of the Raging Storm. Seems like a very fun card that could speed up a game.

Elspeth, Sun's Champion seems to be very versatile, she can make tokens, kill big creatures, make a crazy good anthem effect. She seems solid all around and I will most likely add her.

Those are the ones that caught my eye, but I am still looking at the other suggestions such as Martial Coup and Hero of Bladehold

Payoff
Due to the going wide strategy the best win conditions would definitely be Craterhoof Behemoth, Beastmaster Ascension, and Triumph of the Hordes as they would all offer quick and efficient ways to end the game.

A really funny card to try and win with would be Crescendo of War. The fact that it gets a counter on each upkeep is pretty wild. This could escalate out of hand quickly and end the game in a grand way.

Removal
With the introduction of the many new token spells I believe Aura Shards is too good of a card to pass up.

All of the removal I have thus far is for creatures and I definitely need my removal to be more flexible. Acidic Slime, Beast Within, and Terastodon are all quite versatile in what they can target and might merit deck slots.

Red doesn't offer many removal spells I'm interested in running. Could possibly side board Shattering Spree and Vandalblast for artifact match-ups.

Both Aura Mutation and Artifact Mutation are both very strong yet incredibly narrow. They both aid in the token strategy but seem to be too niche when instead I could run broader removal spells.

Recursion
Due to this being a creature based deck I believe that the recursion should only be run if it is slapped onto a creature. The best of these being Eternal Witness and Sun Titan which I will add simply for their outstanding utility.

Genesis is a card that have recently stumbled on and I think it offers a good amount of value but I would love to hear you're opinion of it.

Card Draw
This is possibly the hardest thing I have encountered while building this deck. The only card that seems to be a no brainer with tokens is Skullclamp.

One major issue for me is trying to decide which is better, risk or reliability. This is shown through the cards of Shamanic Revelation compared to Harmonize. One guarantees 3 cards whereas the other offers much less or much more, which makes it hard for me to choose. Which do you feel outweighs the other?

Fecundity is another weird one as if I do successfully pillow fort up and my opponents begin to solely attack each other they will be drawing more cards than me with my own card.

Mentor of the Meek seems to be one of the best card draw spells available to us for this strategy.

Protection
I really like the Boros Charm do to it protecting permanents and not just creatures.

Dauntless Escort is also an interesting card I have seen to protect my creatures.

I agree with most of your card choices. Mirari's Wake seems better than Resurgence since it's easier to get immediate value from Wake and Resurgence won't trigger off a lot of your effects. Sun Titan, Genesis, and Eternal Witness seem like a great core for recursion. I think you should for sure test Crescendo of War; I determined it and Tempt with Glory to be too likely to backfire for my own deck's tastes but they certainly seem fun and worth experimenting with.

Some of the cards you wonder about are pretty metagame dependent. For example, in my metagame Artifact Mutation will almost always have a target and net 3+ tokens, while Aura Mutation is going to be dead too often to run over something more versatile like Beast Within or Krosan Grip or more powerful like Grasp of Fate. Your meta might have a few enchantress opponents that make Aura a little better. Likewise Hunted Dragon - in my meta it's fine, but the first strike blanking your ground pounders (especially Gahiji) might be too much for your deck and meta. And upon reflection I'd definitely start with Harmonize, to ensure you can use your draw to reload post board-wipe instead of using it to snowball out of control pre board-wipe. Fecundity is indeed risky. I think I mentioned in some DMs that my Gahiji deck was built to win back my playgroup and not necessarily to win, although it has won a few games - and Fecundity is definitely a result of that playstyle and theme as it's caused me to throw a few times.

For your last few slots, I will say again that in my deck Rite of the Raging Storm and Dragonlair Spider have been total rockstars, and those cards (and possibly similar cards like Akroan Horse, Managorger Hydra, Death by Dragons, and Forgotten Ancient) are worthy inclusions in a token political Gahiji deck.