Jobs:
Obstertrician, which can involve performing ultrasounds on other sims, telling them the gender, regular appointments, and for the birth. Although that would most likely take place in a rabbit hole.
Any Doctor Job like in previous games but, there can be a trauma doctor, a plastic surgeon, you could actually watch them perform the surgery!
President: As aforementioned by someone, they could have an election. There can be two parties and it could be some made up ones like they did in Sims Medieval in regards to religions.
Priest: They unite Sims in Holy Matrimony ;D In an actual church.
A Lawyer that would be an amazing job for sims that are being sued or are injured on the job etc...
Mechanic: Someone to work on cars or if they break down to fix it/tow it away.
Actors/Directors/: This job should return but not just any sim can be a celebrity. That became annoying once I saw that my Sims' child was born a celebrity even though none of my other Sims were.
A stripper (In the game they called them Party Dancers?) They could do this at bachelor/bacherlorette parties and when they strip it can be pixelated so they won't have to up the rating :p
Restraunt Owner/Waiter or Waitress/ Busboy: I think this would be in addition to the Chef job and you can actually see inside the diner or resteraunt or cafe.
Airforce/Army/CoastGuard/Marines/Navy They should add more military branches and allow you to have the option of sending them off to war.
Teachers/Principals/Professors: The school need not be a rabbit hole, you could actually see them teaching the children and you could control the class whether its allowing the class to run amuck or be an extremely strict teacher. Same applies with a principal allowing students to run wild throughout the school
Hair Stylist/Barber: This coincides with adding hair growth to The Sims 4, so their can be hair stylists to either style, cut, or dye hair.
Thats all I can think of at the top of my head ^.^