The Regeneration trait was meant to represent, as Marco said, basically the peak of the Imperium's restorative technology (if any non-mechanicus member were to be able to get it, surely the most likely candidate would be an Inquisitor? Inquisitors represent pretty much the top of the Imperial Hierarchy in many ways, particularly with regard to influence and contacts). The idea was that his technology was unable to repair the damage done by this particularly virulent Chaos-tainted virus, but it keeps the Inquisitor's body in the exact same state it is now in. He'll never get back the losses he made to decay, but his body will now require a hell of a beating before it can't go back to how it is now.
With regards to your suggestions, i like them. However, I do wonder about the half T to the head. While it has its advantages in terms of game balance, if we consider the myth of the zombie, the reason we're always told to 'aim for the head' isn't because the zombie's head is weaker than that of a human, but because its everywhere else is, for all intents and purposes, stronger (not stronger in a literal sense, but in the sense that a zombie can't be incapacitated by pain etc....) The zombie's brain is the point we aim for, not because it's unusually weak, but because it's all the zombie requires, unlike a human who requires most of his body to function (at least in the short term...).
Still, I was considering the Flesh Wound ability for them, as well as the Corpse Armour. As for Canniabl Hunger, because these characters are mainly bodily, rather than mentally degenerated, I can't see it being too much of an issue, but I am going to have a character who was particularly badly affected, whose sanity has 'taken one for the team', and he will have both Psychopath and Cannibal hunger, to represent the fact that he is a lot closer to zombification than his comrades...
Thanks for the comments.