keep in mind its only TV-14 now and look at what they've aired. @ TV-MA given some of the gore that has happened on Breaking Bad, I'm sure they can get away with pretty much everything in the comics if they don't shoot it frame by frame but rather film it more cinematically, i.e. Tyrese's beheading (have Tyrese kneeling, Governor standing over him with the sword threatening Rick, and then him bringing down the sword, and instead of showing him cutting through his head show Rick's face as it happens and then quickly move the camera to the corpse to confirm he's dead. Nothing about his daughter is THAT unairable, its him pulling teeth from a zombie, which they can get around with camera angles again and then making out with her?
The zombies/prison fence is also plausible within the tv zombies, the ones in the 2nd episode are a mini herd to explain how their weight brought down the fence, in the prison they come up with ways to thin the herd, and almost a year passes by the time the prison saga is over, even if part of their brain is still active, their muscles will have degenerated quite a bit and they won't be as strong.
I do agree that Governor should not be a season 2 likelihood as I have said before, if anything having Rick see the helicopter (again) would be a good way to close off the 2nd season w/ a cliffhanger for tv viewers and a nod to comic readers that Governor is incoming, much like how Jenner's joke about Carl is a nod telling us that Shane's days are numbered for next season.