With the wonky shape, it might be easier to build a run that the coop would sit inside of. But that makes it pretty non-portable. Maybe look at the coop design page for some potential run ideas that could be removed/attached during the moving phase.
No, it doesn't really NEED sunlight if it's opened up during the day. But I'd make sure that I'm out early to open them up. Sometimes I don't get out until after 10, especially when it's subzero outside, so I'm glad for my windows. I just figured that it would be mighty dark inside that barrel.
They don't really need food/water at night. They're sleeping and have bad eyesight in the dark. But again, I'd be sure to let them out on the early side so they can rehydrate in the morning.
Raccoons live in all environments. If you let your chickens free range (no run), especially unattended, be prepared for some losses.