I guess it's time for me to chime in after 60+ posts of people attempting to "define" virginity. My opinion is......what does it matter? In my opinion the church has placed soooo much emphasis in virginity that our young adults and teens have completely lost sight of the ball which is sexual purity.
I've heard young people brag about still being virgins when what they really mean is they are "technical virgins." In other words they've engaged in mutual masturbation, oral sex, and for some even anal sex but they're proud of their virginity because they haven't engaged in vaginal intercourse. The church needs to drop the emphasis on virginity which once it's lost can never be regained and ends up leaving many young people feeling as if they are second class citizens among the church because they fell in a moment of weakness or were robbed of their "virtue."
Christ when he encountered people He told them "Go and sin no more," in other words He emphasized the future not the past and He spent a lot of time blasting those who followed the letter of the law (in this case virginity) and completely missed the spirit of the law (sexual purity). We as the church need to forget about the big "V" which once it is lost can never be regained, and shift our emphasis to the true spirit of the scripture which is a lifestyle of sexual purity which cannot be stolen and can be regained.
I can agree to you to a certain extent. I've seen posts on other forums about some of the 'purity' and virginity movements. One woman was disappointed with her sex life because she had been taught that if she waited, she'd have a great sex life. She posted that she wished she hadn't waited. I pointed out that by waiting, she was abstaining against fornication, which is a sin against God. The issue is loving God and serving him, not how great your sex life is going to feel.
There is also the problem of kids having fornicated and then going to some kind of church event that focuses so much on not losing virginity, and not focusing on staying pure where you are now. The Bible teaches us to abstain from fornication, and that is an important message for those who have sinned and lost their virginity. Like you point out, engaging in other sexual sin is a problem, and a focus exclusively on 'technical virginity' doesn't discourage other sexual sins.
Be that as it may, virginity does have value. That's one of the reasons why it is so awful to rape a virgin. It's a rape, which is awful, but it's also stealing virginity as well, which does have value. The Bible puts some value on virginity. A woman who lost it by playing the harlot in her father's house who got married off as a virgin could be stoned. God allowed Midianite virgins to be spared after a battle, but not wives. When Genesis first describes Rebecca, it tells us that she was beautiful and that she was a virgin. Apparently, both are desirable traits.
Practically, there is research to show that if a bride is a virgin at marriage (or only sleeps with her husband) she is less likely to divorce later on. This day and age, that's a big deal. The Bible warns that even sex with a harlot causes a man to become one flesh with her. Having sex and losing virginity is a big deal. It causes one to become one flesh with another. Even in the case of a rape in the Old Testament, the rapist had to marry his victim if the bride's father would agree to it. This shows how important the issue of two becoming one flesh is.