Um, "nothing", "not much any longer", "nothing", and "usually a whole lot".
Don't forget that sexual dimorphism serves a critical purpose. Since we're highly social creatures, we can delegate some of that to others without problem.
The rest of your post is quite insightful, and even the rest of this list...but...given that romance is distinguished from friendship by its role in pair-bonding potential parents (hi, biology!), the last one is a bit, well, missing the whole story.