How do I keep this offense off my record? What is deferred ajustification? Is there like a plea deal I can do or what can I do?

You have a right to court appointed counsel, if you cannot afford your own lawyer. Exercise that right.

I'm a 15 year old girl can a date a 19 year old

This is a bad idea. He can get into a lot of trouble if anyone even so much as thinks you two had sexual contact.

What is the most sever and least sever sentence they can receive?

http://www.myindianadefenselawyer.com/criminal-charges/theft-shoplifting/

What's the expected outcome if I called her tonight and informed her that I had a family emergency and left to north Carolina

Who knows? Thus far she has been quite understanding for a PO. Many would have violated you the moment they learned you were no longer in NC and...

Impossible to predict on such limited information. You've been charged with a crime. Don't mess about. Get a lawyer.

Looking for a 2nd opinion.

Look for a local civil rights attorney. Schedule a consultation. If they take your case on a contingent basis, great you have a case. If they ask...

Can I purposefully terminate myself from the ignition interlock program?

Don't get purposefully kicked out. Follow the advice above and voluntarily take the suspension.

Will I be able to buy a firearm with only one felony theft conviction

Firearms disabilities have two sources: state law and federal law. If you were convicted of an offense which could have been punished by more than...

Ask your PO. We don't have the terms of your probation in front of us.

What can i do to fight this and end my probation once and for all?

You should get a lawyer. They aren't going to take you seriously.