I hope that on a professional level people are able to look past your scars and see the potential you have, and when you graduate the professional you are.
On a people level I am not so optimistic. Like someone above said, humans are humans. and unfortunately sometimes human's ignorance clouds better judgement.
All I can say is good luck in school, I am glad you have found other ways to deal with your problems, and I wish you all the best, nursing is definitely a profession that can leave you with a ton of self satisfaction.
I don't know if I personally would take the direction of hiding what they were and tring to change the subject if asked about it, unfortunately that only allows people to form their own opinion of their origin and breeds suspicion.
I would never bring the subject up as a form of attention seeking, but if were asked I think I would be open and honest, but also make it clear that it was a very different time in my life, and that I have grown and have learned to deal with things in other ways.