I think most Walking Dead fans can agree that FTWD isn't living up to its potential for many reasons, but what would you change to make a more compelling show?
I would have liked to have the main character start off as someone who was a bad apple even before the apocalypse, like maybe a gang member who had already killed someone. Perhaps this was a troubled urban youth peer-pressured into gang violence, and conflicted about it (a bit like American History X). Someone who is involved with some dangerous lowlife opportunistic people but also who would have a struggling family that they care about.
Also, the "slow burn" approach should have been much slower and more chaotic. There should have been a significant, sudden, and terrifying zombie outbreak in one or more major cities shown within the first few minutes of the show (which would have been dealt with promptly), and then the media/societal/political/religious fallout of that could have been explored for at least a season.
The absolute urban chaos that would result from the fear of this sort of pandemic would be amazing to explore: religious leaders proclaiming judgement day, mass suicides, looting, fake "cures" peddled on the streets, misinformation.
There'd be a little while where law and order starts to break down, but people still think that "the system" will remain intact enough to justify sprees of robberies, necessitate doomed evacuation and refugee camps, and generally result in the tragic deaths of everyone who's trying to keep it together (all the police, firefighters, rescue workers, humanitarians, etc).
You'd also have people breaking and entering, raping and murdering, and entire class uprising to the level of lower classes invading and taking over the upscale communities and mansions.
Each of these things could have been an entire episode. By the end of the first season, the TV's all go to static.