Trying to combine two good decks to make a better one rarely works, and confuses the deck and it's gameplan. For example, the draw 7 argument should be moot because all three belong in Shop slaver, and adding Mana Drain only confuses its gameplan.
So Chalices are out for now. The question becomes what to replace it with. I realized that one card that could be tried in the deck was Mana Drain.
Yes, this would bring it to the point of being almost a Control Slaver deck with a weird mana base. This is true, except this is not necessarily a bad thing.
Mana Drain is a terrible option for the deck simply because it is so tempermental. Discussing the Gilded Lotus leading to easier Drains, if you have a Gilded out, you should be accelerating your draw and seize the beatdown role, not switch roles.
Your overall role is beatdown using Force to power through your threats (ideally - although there are must-counter spells), and your mana allowance every turn is meant to accelerate your spells out. Mana Drain also disrupts the use of Workshop. Again, bearing in mind that you're using Gilded to power your Draw engine or kill cards, a first turn Workshop means third turn Drain up, at which case
you do not need the boost of Mana Drain mana. In addition you can't control the game without losing your tempo as the beatdown.
Consider your ideal. Turn two Mana Drain using the mana for TFK the next turn. Seems fine enough. However the idea here is that you're trying to pressure the control player through a barrage of threats. That's why you need the full array of three-mana Draw 7s in Workshop slaver - so you'll force one through - and essentially, that's all you need to get started. You're trying to force through the TFK on their turn to leave them vulnerable on yours. By waiting for a spell for ther reactive Mana Drain, you lose the oppurtunity to play two draw spells, and therefore, slow your own development.
#1) Lack of Workshop brokenness in opening hand is bad.
#2) Overall, this deck doesn't have enough control to wrestle it away from the faster combo decks. You rely on getting your combo before them.
#3) Chalice of the Void is only good at X = 2.
#1 needs minimization, but it's not simple.
#2 might be a bit of a bias, since I went something like 1-19 against Bryan Finch's Dragon deck, even though, against a lot of other combo decks, I can work faster than they can.
#3 is what brings me here. Chalice for zero is utterly random, Chalice for 1 kills 9 of your cards, Chalice for 3 completely decimates your draw engine.
I believe you are misinterpreting Chalice's strengths. Going first, Chalice for zero or one has its strengths. A Chalice for zero after you've had an oppurtunity to drop moxen is random - but is an option which slows the opponent severely, as well as skews the power level of a given hand.
However, should you not have that option, Chalice for one or three remains powerful. Right now, with the metagame giving strength to combo, Fish, Hulk, and both slavers, Chalice for one slows down their engine - and except for the combo matchups, allows you to go the beatdown route in a manner that hurts your opponent more than you.
Chalice for three stops your draw engine. Against Hulk, it essentially wins the game.
Your testing against Dragon shows that Dragon can easily play around Chalice for two, granted. But agaisnt Draw 7 and Two-land Belcher, getting an early Chalice goes a long way to buying you enough time to get a Slaver active - here you are not the beatdown at the onset of the match, you are the control, if you try to out-combo them, you will fail miserably.
The idea with Chalice is that you use it not as a prison-lock tool where you're trying to stop their win, but as disruption. As you're beginning to power out threats, dropping Chalice for zero or one does one of the following - it either slows their development, and thus, their ability to stop your threats, or it prevents their utility options (i.e. Brainstorm), thus also slowing their options for keeping up with your speed. You're not trying to use it as a I-win-the-game card - although that is certainly an option. Tossing is for a lower option doesn't win the game alright, but it's meant to slow them more than it slows you.\
By practicing using the Chalice purely as a disruption tool (unless a superior option presents itself - the idea is that you're not waiting for one to appear) to slow your opponent down, you will find that it becomes more useful if used correctly.
Also, addressing your sideboard.
3 Viashino Heretic
3 Blue Elemental Blast
3 Tormod's Crypt
2 Rack and Ruin
1 Duplicant
1 Platinum Angel
1 Red Elemental Blast
1 Wheel of Fortune
You lack higher number of Red Elemental Blasts, Gorilla Shamans, and Trinisphere, which contribute to your woes against various decks. Many of these cards (Wheel, the creatures) are only there because the deck is so confused as to what it's trying to do that it must leave out ideal cards.
