What makes a good Zombie story?
Really it comes down to two real factors. One is the clear one being that theres a small group of survivors facing unbeatable numbers of the undead. Its a staple, but if handled correctly then it can make a pretty compelling story. However the other is what makes a zombie story fantastic, and that is if the Zombies are NOT the TRUE evil in the story, Humanity is. Treating the zombies as a virus, as opposed to monsters is vital for this. The zombies are no better than wolves,bears, tigers or any other living creatures that usually people are fed to. The only things that make the zombies different is that people can become them if scratched, or bitten, or spat on, or after a night of hot passionate love.
It all depends on the approach. Even movies like Zombieland dont paint the heroes as heroic, because they are not. Tv shows like the Walking Dead Really capitalize on the human is evil trope, because when people are in danger they do cruel and crazy things under the guise of fear.
Is it possible to Quarantine an entire town?
I think that depends on the towns size really. If its a small enough town, maybe. But realistically there is a lot of factors to consider and then you have to remember that there were people who snuck by borders and security measures during the likes of the Berlin Wall. Which honestly would also probably happen today, if one was made. Then you have the likes of social media as well, sending the outside public into an outcry over how they people inside of the lockup would be treated. It would only be a matter of time before people either rebelled, escaped, or the entire town was wiped off the map.
Predictable or Enjoyable?
Depends once again on how well its handled. If the dots connect, and its not blatantly obvious from the start then yes it can be enjoyable. Look at Umbrella, they are supposed to be a pharma group, not a zombie making machine. Yet they have enough power because of how great their products were beforehand, and had contracts with the government for biological weapons. That being said, you can always have a shadow organization that was there all along. Like have the people see the symbol but not know its name till the end, after the hero discovers hey that was the name on my shrinks clipboard.
Protagonist
This can be almost anyone as long as they dont ALWAYS crumble at the sign of the dead/villains. Its not about being a full blown pacifist, but maybe not go all guns blazing at the zombies. You dont need to be a genius, and you dont need to be an expert survivalist, but you do need to have some common sense. Honestly its fine being hesitant and cowardly because lets face it your facing 50 to 1 odds, and you may just have a nail gun. Wear clothes that are harder to rip through and easy to run in. (Leather jacket, and some comfy pants maybe? Just make sure you can run in them). Its all about the journey of the cahracters and how they bounce back and fourth off other characters.
Names
Names can make or break a character. Sometimes it works, other times it sucks. Like you dont need to know the main character watched a cat piss itself if its not neccessary. I think this is where nicknames come in handy. Have them go by nicknames instead of anything else might make the character keep a layer of mystery while also appear really human, because someone gave them that nickname and they carry it on.