To be clear, theres absolutely nothing wrong with this, and sideboard guides and decklists are the lifeblood of Magic content
Capricious Efreet is kind of cool if you want sacrifice triggers anyway, and if there are two horrid enchantments out there to target, say a Rhystic Study and a Necropotence, well, you have a 67% chance of nabbing one
Mickey Mouse, Detective costs three ink to play, but it's not inkable
"Flashforward [cost]" means "You may cast this card from exile by paying [cost] rather than paying its mana cost" and "If the flashforward cost was paid, put this card on the bottom of its owner's library instead of putting it anywhere else any time it would leave the stack." You must still follow any timing restrictions and permissions, including those based on the card's type
Then any other player may pay 2 life
Then sacrifice the Putrid Goblin with the Skirk Prospector ability to add mana