Another great episode!
Zombies with no bite marks = the virus is airborne and everyone is infected. They aren't going to need to die before turning, either. It's a ticking clock for everyone.
That's the gut-punch twist this story needs. For people to turn after death is not really going to come across as being so dire - all that means if someone dies of natural causes or is executed (like maybe is happening next week?) you shoot em in the head. Is that really so traumatic compared with everything else they've experienced?
And that's the CDC guy's secret that Rick hasn't told everyone - to this point, he didn't really believe it. I noticed how he lingered and looked at the bodies, as though he was remembering...
The survivors so far have been doubly lucky - they didn't get bit, and they have genetic resistance to being infected without being bit. Some might be immune, which they can tell if they actually go through the zombification process and revive without being turned. I think that's what happened to Rick already, and that his immunity will become an important point after everyone realizes that there really is no hope for humanity.
The plot twist can't really be that there's no hope, period - there's no place for the story to go from there. A slim hope, centered on the main character (and possibly also his son and unborn baby since the immunity is probably genetic) works much better.
As for the Fight in the Kitchen, I was 100% on Andrea's side - Lori just came off as a bitch, and Maggie wasn't much better.
As for the division of labor, it's insane that this group isn't training every able-bodied adult in the use of firearms, or better, crossbows (Herschell must be able to tell them the location of the nearest sporting goods store!) because Rick's idea to use knives is pretty whack. Letting a zombie get within bite range? I'd rather take my chances with a gun until I can find a damn crossbow. Even something like a sledgehammer would be preferable to a knife. Anything that will keep you out of bite range.
If all the adults rotate zombie-spotting duties, then all the adults can cook and do laundry as well. Getting as many people into rotation for zombie-spotting is crucial because having to do a stressful job where you always must be alert, yet nothing usually happens, is very hard for people to keep up for hours on end. I'd say shifts of 2 or 3 hours would be optimal before fresh eyes should be brought on. There should be at least two people on duty at all times - nobody has eyes in the back of their head!
If Darryl or Shane doesn't like to do laundry, tough. It's a zombie apocalypse, or haven't you heard, and everyone needs to adjust.