Couple of thoughts:
Suggestion 1
Someone recommended this a while back, and this still isn't implemented. This would be great for players that go Shade, and it would reward them for doing so. I would say instead of determining points based on how many bullets blocked, the points would be rewarded based on how much damage was blocked from any source of damage.
Suggestion 2
Can't say much about this because I feel like this is RNG-based for how many points you get for damaging humans with puke as Pukepus or Swamp Legion.
Suggestion 3
Sorry, this is a no for me. The Juggernaut is already powerful as it is, and this is something players can't get whenever they want. Because only the last human can become the Juggernaut, that means getting the boss itself is out of the player's control, and having Juggernaut cards, while helpful, would be rarely used because of this.
Suggestion 4
I agree with cards that decrease the delay in-between heals, but I don't agree with cards increasing the flat heal rate. That could be an unfair advantage for the humans because if someone's low on health, having increased flat healing could potentially restore 1/4, 1/3, or 1/2 of that player's health with one heal, and that's too damn strong for zombies to go up against.