Retirement and mentoring

Hi all, I have been making my Sims work, go to parties, socialise, etc. As I mentioned in my previous post, two of my Sims have four traits, my third Sim is waiting to unlock the fourth trait. I am level 17 currently, and I started to get a bit worried if my Sims are bugged or not. Is this normal? The reason why I am worried is because my game is currently bugged, with the fourth Sim slot not working correctly and not letting me to make a Sim. Technical support is aware of it and trying to fix the bug.

Anyway, one of my Sims is now working on her second career after she finished the Barista one. My second Sim is working on "Out of the Frying Pan" career story and hasn't finished that one. They don't have kids yet, since everything cost a lot of Simoleons. Do I have to max out on everything before retirement message will pop up?

I am sorry, I am new to this game. Any help will be appreciated.