Nice! digging the idea, I'd love to get some people together to try something like this.
Although I don't really like the 1/2 of your action/hole action think you got going. I think a points system ware actions drawn from a pool (much like the Fallout series' Action Points) might streamline things a bit more/ allow some characters to gain the ability to do more in a turn/ make trivial tasks, like flipping a light switch, turning a doorknob picking something up like a key, bottle of Everclear(For Malatovs of course

), ect. something large might use more of your "action Points" for that turn. Also, with a point system like this not limiting you to 1-2 actions you can have weapons that would take more effort/skill to fire( a rocket Launcher or big ass Machine Gun you find on some abandoned military vehicle) take up more of your pool and smaller ones(knives & Pistols come to mind) less
I'm assuming this would be an ongoing campaign, like Necromunda, so characters build there skills, get new weapons/abilitys, ect.
that being said, I'm going to seriously try and talk some friends into trying something like this, keep posting, would like to see updates on weapons and Rules refinement
also wondering if this is taking place in the
40k universe or not. you said something about
40k zombie bum rush, then used a Lumber Jack for a Char. Example. Just curious, but I'm thinking that a Space Marine Zed
Tac squad kinda defeats the purpose. and wasn't space hulk basically the same thing? just with Nids?
Anyway, Great Idea, Love to see more on this