I really like this idea! Like working for gold and stuff. The only thing i dont like is the whole shifts idea. I really only play when i have time... so that wouldnt work out so well for me if i had to go on at a certain time every day.
Eating for energy is a lot better than waiting an hour for it to refill or having to pay for it. Or maybe energy wisps would be cool.
And there doesn't have to be just restaurants. there could be some other form of work. I have no idea of what those could be but i think its a good ideA. So instead of shifts you could just start working at any time but only a certainamount of people can work at once... just so that theres not too many people working and not enough eating.