You should check out the Masters of the Forge podcast. They did a Malal episode a while back and introduced their own take on Malal rules in it.
As for your own rules, I'm personally not a big fan of random charts that have to be rolled every turn.
The 1-2 result isn't my cup of tea for the same reason I don't like the potentially self-destructive results on the daemons' warp storm table: it's suspension of disbelief wrecking for me to imagine this army killing a random guy every 10 seconds, and it lends itself to more of an ork-style sense of comedy lolrandom than to a badass elemental force of utter entropy.
The 3-4 result is probably fine, but all these random rules don't really give me a solid mental image of these guys. Plague Marines are tough. Noise marines are loud. Berzerkers stab stuff. I get that these guys are all about chaos, but how would someone describe their appearance, behavior, etc. to someone else? Their various benefits just seem heavy on an abstract sort of zany random game mechanicness rather than representing something I can sink my fluff fangs into. ^_^;
The 5-6 is neat, but waaaaaay too much book keeping for my taste. You have to keep track of each kill made in the shooting, psychic(?), rand assault phases each turn, roll a batch of dice, keep track of their starting size and who's dead, and then remember that they may or may not now have a +1 to their armor save, but then you can forget all that once your next turn starts because now they're back to normal armor. And then you get to keep track of all that a couple more times for each unit of these guys in your army after the first.
Also, would the +1 armor save kick in if you brought several guys back to life that turn and then had 5+s left over, or would it only kick in if the unit was at full strength *before* you rolled your 5+'s? Also, is that a +1 armor save for each 5+ or just a flat +1 if any 5+'s are rolled? It might matter when it comes to powers like Jinx that lower your armor save.
I'm glad to see you're having fun homebrewing. I would recommend clarifying who and what these guys are exactly, and then tweaking your rules to require less bookkeeping and reflect the fluff you've come up with accordingly.