There was a question? Amber is not Amazi-girl out of a sense of altruism. She does it to have an outlet to dump her more violent urges. She has even said as much. Amazi-girl gets to beat up on 'bad guys' so Amber doesn't have to deal with those feelings. Unfortunately for her, things don't work that way. Amber still gets those urges... see running into Sal and her reaction to it. Instead of dealing with her mental health problems in a healthy manner, she is compounding them by creating an alternate identity.
I don't think she is specifically self destructive. As in, I don't think she has a conscious desire to die, probably not even a subconscious desire. But she is quite frankly been running to close to the odds already. It's only a matter of time until she runs into someone she can't intimidate or beat down. Or she'll wind up doing some insanely dangerous stunt when someone isn't around to save her life. Life isn't like super hero comics. Even those who live as real life super heroes know that, which is why they don't do the crazy stuff Amazi-girl does. If she doesn't stop, then eventually something bad is going to happen. Best case? She'll get caught playing vigilante and arrested. Worst case? Another stunt pulled like when she saved Becky will wind up with her dead. Most likely she'll wind up getting seriously injured and having her 'secret identity' revealed... with the attendant police questioning and probably arrest.
She has done some good as Amazi-girl, sure. She might even convince herself sometimes that is why she does it. But if she doesn't end it herself, sooner rather than later, something else is going to... and end it badly.