Emrakul is better than a second staff because he hard counters mill strategies, and there are a few of those I'm modern. Heartless summoning combo and lantern control are two off the top of my head.
Sure it could be "win more" but when you have infinite mana, but that isn't really a problem.
If you want competitive wincons though, a second Auriok Salvagers probably best replaces Memnarch as it sets you up for a more powerful long game. Having a recurring value engine with the Spellbomb can win the game a significant amount of the time against decks that can actually lock you off of the combo.

Also, if the aforementioned platinum angel had persist as mentioned, it would just come back after the annihilator triggers and kills it. I guess eventually after enough turns after they ran out of permanents it would work, but the oddball decks that run that kind of combo don't take that long to go off after a solid stall tactic is in place.

Ok so, I want to try to get this deck finished by Monday, 1/11/2019. As I mentioned earlier I made the decision to attend GP Louisville (which I am paying for myself using a large portion of my college money). It will probably be the only GP I ever attend, but it's more than nothing. I want to have the deck finalized by Monday so I can order any and all cards that I am missing and have them in paper to start testing the deck out.
Until then, I am willing to take any and all suggestions on the deck, no matter how far out they are. If anyone wants to chat on tappedout about the list, I am also open to that.

....Finished by 2019? Or 2016?

I really hope you do well at that GP. I can help you tune this deck later, but I'm a little busy right now. I really want to help you make this deck good though.

Wanna turn on chat to make it more efficient? Or any other easy things that can make working on it easier?

Chat or skype both work for me, and yes i meant 2016 :P

The one thing I am noticing that this deck could use is an additional wincon in the cmc=2 spot. I've used Profane Command to revive into the combo, with a Muddle the Mixture in hand, and accordingly lost because I had no way to use the mana despite having a tutor in hand. Also, being able to fetch a wincon with Artificer's Intuition without having Auriok Salvagers would make AI much better.

Is having both Blue Sun's Zenith and Staff of Domination necessary? I think there used to be a reason for needing both, but I'm forgetting what that was. I don't think there are any scenarios in which you can tutor for one, but not the other, making one of them not very good in here.

Staff worked with fabricate, which is gone now. I'll have to look into other 2 CMC wincons.
There are no 0-1 CMC artifacts that can act as a wincon, to my knowledge.

Been thinking about maybe possibly including Hangarback Walker in the SB for those match-ups like eldrazi control and the BGx decks.

Or even main board. An infinitely large hangarback that makes as many thopters when it dies creates a pseudo wincon for AI to fetch. It could replace the staff.

I actually like staff more than Blue Sun's Zenith, I think. Not sure. Tapping down is great vs midrange, although so is card advantage.

1-of Hangarback seems nice, but the anti-synergy with Vial is notable. Hangarback does allow some nice blocking shenanigans against aggro such as Zoo or even Jund.

Have you ever considered hand disruption? Inquisition of Kozilek and Thoughtseize are the best around, and they can serve to remove burn spells, Abrupt Decay, counterspells, Lightning Bolt, opposing discard, pretty much everything. They're expensive, especially with the buyouts, but a splash of hand removal could be what this deck needs to beat midrange decks.

I tested playing with 2 Hangarback instead of Memnarch and BSZ, playing my copied version of this deck vs the original. The Hangarback version (henceforth known as 'Minewalker') had to use Profane Command to keep the Minefield off of the combo, then topdecked a Muddle the Mixture and comboed off, but with no Profane Command to transmute for. Minewalker just transmuted for Artificer's Intuition then ditched the extra Pili-Pala in their hand for a 99/99 Hangarback Walker which won the game. Moral of the story: Hangarback has already changed the outcome in all 1 games that I've played with it.

Damnable Pact is just bad to me. I'd rather see a second Profane Command over it, which actually wouldn't be that bad of an idea.

So then here is the question: is Hangarback Walker better than a second Profane Command? I'm inclined to choose the hangarback, because it can stall creature decks for so long, which is something the deck struggles with.

Is there anything like Bonfire of the Damned at cmc=2 in Esper?

On a side note, I think you should have a 1-of Steam Vents in here because you will want to use Pyrite Spellbomb for creature burn against decks like Merfolk. Also, with Auriok Salvagers on the field, you can soft lock creature decks by getting a 'free' shock for 4 mana, which is really effective at keeping them off the board. Plus, adding a Steam Vents gives you access to a red X burn spell for cmc 2 as a wincon + removal.

EDIT: Aurelia's Fury looks pretty nice, although a little hard to cast...