I suspect you have to find another title for the book, and not include "romance" in the title due to the bastardization of the word these days.
Maybe sell the idea as "Social interaction of the inner sea" or "Social Culture of the inner sea" or something that is way more neutral than you would like it to be.
I would call it something like "Families of the Inner Sea" and have it encompass more than just courtship, make it more about the whole range of a Player Character's important social ties to various NPCs. Perhaps include a number of prominent tribes, bloodlines, and noble families that the player can be a part of and have traits that represent their upbringing. Courtship would naturally fit into the book as a means by which families form and grow, and as a way for players to form new ties to important NPCs.
I for one would greatly appreciate details on Wedding and Funeral traditions across the Inner Sea. How many novels and movies include a prominent scene at one of these two events? It's practically a given.