I think it would be fine to deny a customer, as it can promote others to sell food as well. People could make more money from fishing and such if there is more need from players to buy it. Probably best to have a rule in place for other stores such as gas station that sells items you can only...
Could add a tool for the fire department to see how the fire started to engage a investigation, might be hard to do but adding some other tasks for the department would increase players playing them and provide more RP
Maybe have some simple rank structure where people can apply to become a Fire Chief and Chief medical officer? And have it like the old PD was where 1lt could be on duty. So 1 chief on duty each time for the medics and FF.
To become those you can either have it a donation rank or apply based on...