It is pretty surprising, isn't it? :P
I find pre-confession romantic dancing to be a little tiring. I would much rather explore characters working through an existing relationship, as it's highly unexplored territory in the field of fiction with a vast wealth of untapped story material. More importantly, it feels more in line with Crescent culture as I've imagined it. Asking people out for dating/courting isn't as big a deal for them as it would be in, say, American culture, since they don't associate any commitment with it like we Westerners do. Responsible or interested family members would interview each other to ascertain the prospective spouse's strengths and weaknesses, and provided everyone agrees, the couple would date/court in order to learn more about each other. They would do so for a short period of time, usually a few months, after which they will either part ways (perhaps temporarily) or make a decision. It's common for them to part ways so they can court other people, but sometimes, a pair clicks so well that they choose to get engaged instead.
Things really only get serious when the pair get engaged. Backing out at this point isn't so easy, and may require some legal proceedings in order to make the split (depending on the prospective couple's emotional and financial investment in the union). Once they're married, they're married forever, backed up by Imperial law, so they need to be completely sure of their choice. Thus, dating should be done frequently and in-depth in order to make sure that the person they marry is the person they want to stay with for life, because once they commit, there's no getting out. So that's the impetus for Ed asking her out early - getting too attached to her before he really gets to know her could be dangerous for them both in the long-term.
The Crescents have many ancestral roots in Asian culture, which is partly where that comes from.