I think another big part of life would be being a doctor, nurse, pharmacist, EMT or medical specialist of some sort. They would be like healers in other MMOs, but instead of people taking damage in battle, people would get 'sicknesses' at random or from some hard to trace sources, or just from each other. It's a cheap almost artificial way to make this profession needed, but it also kinda reflects real life. In the larger game, instead of playing 'against' each other like cops and robbers, or politicians, or businessmen, doctors are primarily playing a PvE game against various diseases that spread if they don't keep them in check. Most diseases would come with a minor debuff for players, encouraging them to go to the doctor, but not making it so mandatory if they just don't feel like it or want to 'walk it off' so to speak. Having a long recovery time in hospitals could make 'death' a big time price to pay in the game, and doctors could make that recovery quicker and allow players to get back in the action faster.
Doctors - The main healers. Can do the work of all the other healers, but can also act as a buff to other healers to make them heal better if they play a 'supervisor role'
Nurses - Do all the work of actually applying tools to people and replenishing their health. Takes a few minutes of 'recovery time.'
Pharmacists - These guys create the medicine
Specialists - Special Doctors are needed for special types of ailments, and carry specific buffs when dealing with those types of problems.
EMTs - Field Doctors, travel with an ambulance, can work with people in the street or bring them back to the Hospital.
Note on Firefighters: Firefights are, in a way, doctors for buildings, preventing the spread of the 'fire' disease. So the same design principles could be used for that much coveted position. It's not a coincidence that EMTs and ambulances are stationed at fire stations.