To justify sex withing marriage then you should fall in love only after marriage. The whole world should start having arranged marriage for that matter.
The reason I say this is because if you read your entire article all over again. You will realize that the justifications you have given against having sex outside marriage applies to love as well.
This is off the topic, I wish there was a way to track this topic so I could know I can go back to this article but I am not sure if it is possible so I don't think I would be coming back to this topic again and reading any reply. So wanted to say Thank you Sarah for a nice article worth reading. :)