Could we create a new hairstyle that's like Paparazzi but completely behind the shoulders?

Do you mean something like ? I'm never against adding new hairstyles, but honestly when it comes to female hairstyles we kind of have enough to at least moderately satisfy whatever your need is. And if you want something more specific and more precise you can always work on getting it released as a Custom Wearable.

I'm not sure how familiar you are with the wardrobe yet, but if you go into it you can go to the Hair tab and from there you can click the "Show locked styles that you haven't currently earned." button and it will show you hairstyles whose color can be customized and once you find a hairstyle you like you can try figuring out how to get it.

You can also go to the Item section of your Wardrobe and under layer select "Head" and then click the check mark to the right that says "All Items" and it will show you every item on Subeta that's in the head layer. A lot of people use that method to see if something like a specific hairstyle exists on site since it's hard to remember every item in existence.