I don't mind pronouns, but still find them very confusing since I don't know who uses what. (I knew a guy who was very masculine by the name of Paris - but did not know he was a him until I met him in person, and was embarrassed to have accidentally referred to him as her.)
Wanted custom content: His/him, They, them, She/her tee shirts. For Sims to wear. I am pretty sure those already exist. Also, just for fun, for those using the royalty mod: Majesty, Thee, thou, thine. There are even some who were born female who identify as females who I have mis-identified just because they had short hair, not wearing makeup, and were wearing hoodies, and some males that I mis-identified from the back because they had long hair. Very embarrassing. (Those born male typically seem to have square jaws, in my experience. Dreamer (comic character in Supergirl TV show) was an exception to this rule though.)
Another wanted custom content: "Don't judge by appearances" T-shirt or pin. Speaking of which, button slogan pins don't seem to be available in Sims 4, though I suppose they could be cloned from the flower pins. Yeah, yeah, my age is showing. I don't know if those have been terribly common since the 80s (we covered our denim vests and baseball hats with them). Now if I could get rid of my crows-feet appearance....
I also want some WIGS in my game. So I can temporarily change hair color for a party without changing the hair color on all outfits of every type. They probably would fit great in a hat slot, like the Princess Leia wig.