I have done some research on this and it appears that all of your arguments received a counter, you just didn't like the answer
. I have already commented on this once but will state this again here. Unless it goes against your personal religious or moral beliefs then there is nothing wrong with premarital sex as long as it is with consenting adults who are either in love or not. If it does go against your religious or moral beliefs you can not impose those beliefs on someone else simply because you believe they are committing a sin, the only thing you can do is wait until you are married.