Hi. I am sure that adults will chime in and can help answer a lot of your questions. Hank is great and I am sure he will respond soon.
I can tell you that laser is not just for cosmetic BUT for medical reasons. You are still young, but many adults have had "changes" in their pws,esp if untreated. You may see some changes at 17, it would depend a lot on location and the depth of your individual pws.
There is always a chance of scarring with laser tx. Unfortunately, you can never say never. But if you see a Vascualr Abnormalities specialist and with the current laser technology, the risk of scarring is there but much better than if you were seeing someone who is NOT a laser specialist for Vascular issues.
Insurance sometimes does cover laser. You made need to fight them and send them letters from doctors about the medical necessity etc. Is your pws causing you pain? Are both your legs equal in size? Do you notice any swelling etc?
Unfortuneately, with the current laser technology, most pws can not be eradicated 100 percent. There is hope for the future though. Technology is always changing.
How many tx's you would need is very hard for anyone to answer you at this point. The Dr may be able to give you a general idea about how much fading to expect and approx. how many BUT they usually want to see some test spot results first or see how the pws responds after one tx.
I am sorry that you have been having some issues with your pws. It will be very good for you to hear from the adults here who live everyday with their pws. I do not have a pws ,it is my daughter. I will not even begin to say that I know what you are going through, because it is not me and I can imagine but I am not the one going through life with a pws. I have the same concerns for my daughter as I hear you and other adults state.
We are all special and unique in our own ways.