I definitely think that emotions are a very important part of the game. (And not just for better success in my Black Widow challenge lol.) I do think Sims should be more reactive to their emotional state. I do think that there should still be a recommended mood for peak job performance, however, a Sims traits should impact their job performance too. Right now I feel like traits and emotions or moodlets kind of like a side carrots and a side of potatoes instead of them being mixed into a stew.
There are many things that need to be worked on but overarching theme for me would just be to make the game a lot more cohesive in all of it's parts.