Yes, you can enjoy DayZ in single-player mode.
Yes, you can enjoy DayZ in single-player mode.
Yes, Dayz is available for single-player mode and has been released. You can check the latest updates for more details.
Dayz hasn't been updated for quite some time, and the best option right now seems to be setting up a private server. I'm not sure why you'd prefer single-player mode when most of the fun comes from interacting with others.
They're developing a single-player DayZ experience, which is in the development stage but not expected soon. Right now they're concentrating on the existing version. A release around 60% seems imminent, featuring a significant update to dx11, which could greatly improve stability. The team hopes this will enhance the overall game.
ArmA 3 demands more tuning than DayZ, with a larger number of options. It tends to run slower and feel less responsive, especially in multiplayer—if you're into zombies, the Breaking Point Modded Exile adds extra flair.