I mostly agree concerning survivor perks, though leader, ninja, non-lethal, supplier and turtle can be decent on the right maps.
Your zombie list is way too short though. Combustible, horrifying, hunter, magnetic, rage, scorching, sick, and thieving are all pretty good.
I don't know what to do about toxic. Sure, it's pretty useless when survivors have medic, friend or holy, but otherwise it can really screw them over. Just straight-up buffing the damage would be too rewarding for someone standing still, though. If it really needs to do anything else, maybe it should either give survivors a slight debuff to their defense from sources other than toxic, or provide a slight health regen, defense or speed bonus to zombies.
In general, though, the balance seems to lean towards zombies. While a few of the survivor perks are slightly op and can be annoying in the right hands, a well-coordinated zombie team should always be able to take them down. Friend needs a nerf and ninja shouldn't give medics a speed bonus, but other than that I'd just like to see some buffs to the unused survivor perks or nerfs to a few key zombie perks.
P.S. Ehhh, I enjoyed one-hit backstabs as much as the next guy, but they don't really need to come back. Maybe a speed debuff, at the most.