I feel like the first episode in season 4 part 2 should only include Rick, Carl and Michonne like issue 49 and most of 50 did. Have Rick and Carl gather their bearings and Michonne might stumble upon a stranger (maybe a hunter? Abraham?) and end up meeting back up together. As a whole i think the 4th season should end with the hunters arc. I remember seeing this article on the wiki and this guy pretty much predicted advertisement for the hunters arc

the dead do not stalk (someone watches rick from afar)

the dead do not eat (this shadowy group sit around a group and they're eating what is obviously a human limb)

the dead do not kill (someones holding rick or daryl or carl or michonne at gunpoint)

the dead do not hunt (the hunters eyes are shown, i feel you can tell a lot about a person by looking into their eyes)

Personally the hunters arc was a favorite of mine. I feel the hunters should be introduced by kidnapping bob, cutting off a limb of his, dropping him off at the church and then the group (especially tyreese) go on this revenge fueld mission to track down the hunters which takes 8 episodes to wrap up. Carol ends up returning but she gets killed by tyreese one sudden night (like when carl killed ben)

It all ends with ricks group outnumbering the hunters and the massacre from the comics happens. Carl witnesses this and he asks his dad, "why would you do something like that?" Rick responds with "i lost my wife, my daughter, my best friend, and my life, i have nothing to be innocent for anymore. i killed those people and i enjoyed it, all of it. cutting them up and burning them, i realize this world makes monsters, whether it be us or the walkers, were all the walking dead, son" Rick walks away and the season ends there.