The lack of heart thing is probably just to show that his body is mostly Zetsu clone with Obito's twisted mentality bonded to it. Kakashi's Raikiri doesn't kill him because there's no organs to shock. Just means that Naruto's Yang Release while chakra cloaked would be super effective like the other zetsu(s) (Have we ever found the Plural for Zetzu?)
The Strongest part of the issue for me is the foreshadowing of Naruto becoming the new Sage of Six paths. He's matured a ton since Jiraiya took a dirt nap and is easily a better hero than most people give him credit for.
The weakest point of the issue for me was the Mist's plan to Bijou bomb the Leaf. Really? You're in the middle of the Third Shinobi War and the best way you can think to use your greatest asset is to let it off its chain in the neighbor's backyard?