Keep the same layer height (.16 initial, .08 layers) and it'll turn out great)
While it's both hilarious and enjoyable to beat your opponent with their own deck, you're also relying on the synergy of your opponent's deck to gain the upper hand
(2018-01-19) Cards owned by your opponents still go to the appropriate graveyard
While there are plenty of other extra turn spells, Capture of Jingzhou is one of the most efficient versions of this effect without any additional conditions
All it would take to fix the issue would be dropping cards like Ragavan, Nimble Pilferer and friends from mythic to rare (which, based on the original definition of what a mythic is supposed to be, probably should be anyway)
Archdruids Charm Though Archdruid's Charms imposing mana cost makes it hard to include in multicolor decks, you should still try