Prismatic Jewel Kit: Proposed nerf sounds like the best solution.
Battlegrounds Battlemaster: If it goes to 6 mana it should become a 7/6 so it’s still a threat body on it’s own.
Kolkar Pack Runner: I’d rather nerf Kolek from the Demon Companion card to give adjacent minions +1 attack instead.
Doomhammer: 6 mana or reduce the total weapon charges by 1-2. Either is fine.
Darkglare: I’m fine with Darkglare going to 3 mana 3/4, it’s healthier, but I think Zoo will die off if it happens because it gains a lot of win% from the Darkglare scams. I really wish Sea Giants were in Standard.
Il’gynoth: Not sure, too busy to try DH yet, expansion is too fun.