You said "optional", and that's all I needed.
I'm one of those whose imagination makes the game so much more interesting than it is at the core. I see things as their equivalent, I emulate what isn't inherent, and whatever I cannot reasonably play, I imagine occurring and follow from there. For personalities, my mind strings together traits, skills, and context clues to create people, not dolls.
A good game system for The Sims must lend itself to those want to paint on a blank canvas, and those who want to read a "choose your own adventure" book. I had to turn off Lifestyles because they tried to tell me who my sims are. Sentiments are more akin to what I prefer, as they just tell me how they feel in the moment, which I can reasonably work with. As for random events--so long as they don't take my sim away from me (by pulling at their autonomy), and instead invite me to explore the possibility, or give me more to add to the story, then that's fine.