What do you want out of a Romance Expansion?

Besides the two mentioned by OP I would want/like:

proposal at a table
holding hands while sitting at a table
play footsie at the table
more romantic social interactions
in-law relationships
make out on the bed
more wedding dresses, suits and hair
bachelor/ette party
throwing rice at weddings
congratulate options on marriage/proposal/new boy- or girlfriend
reworked dates
chemistry system
zodiac signs
an event where you can invite the families of both partners at the same time to get to know each other
photo booth
first impression sentiments
one sided relationships
a social interaction to introduce your partner to a family member
buyable chocolates, jewellry and stuff as gifts
making out on a rug besides the fire
picnic blanket with unique interactions
a faithful reward trait that can either be purchased or obtained via gameplay (could also by a lifestyle your Sims develop)