This deck already has two artifact cost reducers (Enthusiastic Mechanaut and Etherium Sculptor), so the third is pretty redundant, and Cloud Key is the worst of these effect due to its cost
Rakdos Cackler A 1-mana creature like Rakdos Cackler is always going to be useful, especially with flexible mana costs
We mostly believe people will know what they're signing up for in a game with Braids as a commander, and as a card in the 99, it is reasonable and acceptable
The powerful Eldrazi costs 13 mana, except it doesnt since that cost is reduced for each card type in your graveyard
You can use these to explore the new set that the Prerelease features while battling other players in your area for even more sweet booster packs
It appears as though Wizards of the Coast did not want to risk the set not selling packs due to mediocre new cards, so they loaded Conspiracy with a bunch of high-quality reprints and a couple of juicy Eternal plants