Leyline of the Void against Grixis faces the same problem Leyline of Sanctity does against Burn. In your opening hand, it's nearly unbeatable. Outside of that, it's too slow and may not even have much of an impact, (and unlike Rest in Peace, it doesn't exile graveyards on ETB, so whatever is in the graveyard beforehand is there to stay.) It's still very good in the right situations though, so keep testing it and see how it works.
With our lists running Liliana of the Veil, Lingering Souls, and (for some) Grafted Wargear, I don't think we have room for another 3-Drop, especially one that dies to Lightning Bolt, and doesn't do much of anything if it does manage to stick.
Drana seems like a trap, to be honest. As good as she is if she connects, she's a 3-drop that dies to bolt for no value and a huge tempo loss, and that alone makes it really hard to justify in Modern.
I'm 100% running Shambling Vents over Mutavault. Coming into play tapped hurts but we want WW and BB on turn 3, so tapping for our colors is critical.
Personally, I'm excited to test the new Gideon, it hasn't got a lot of discussion here, but it seems really playable. 5/5 Beatstick, Token Generator, or a permanent anthem are all relevant modes to our gameplan.
The BWR list seems clunky considering it has 11 3-drops. A big part of the power of Bob in Jund is being able to cast multiple spells a turn and proactively use your card advantage. I definitely would cut down on the number of Kolaghan's Command. 4 is way too many.
I ran one Stony Silence in my board at GP Charlotte last month. Maybe 2 is the right number but it seemed OK as a 1-of. It's worth at least one spot though.
And the new Liliana just seems worse than Liliana of the Veil. The plus abilities are the same. LotV's minus is better as it's removal and we don't have enough relevant creatures to recur to make the new one's minus worth it. Add in the fact that new Lili a 3-drop that dies to bolt for no value and that we have to meet a condition to flip her and LotV just blows her out of the water. Feel free to test it and prove me wrong though, I'd love for this deck to get new toys to play with.