Nothing more you can do. Let her learn the hard way, she's gonna do it anyway. Don't stress yourself out over it.
Always a possibility too. Unfortunately there's no way to truly know unless it's tested.
If Mira wont listen to you then i suggest you been there for here when she falls. Be the friend that was smart enough to give her advice and be there when they are wrong so you can pick up the pieces.
People can change for the better but it takes a long time. I suggest you watch how he acts and see if you can see any small little changes in him for the better. if he doesn't then just be there for your friend. if he does change then i suggest you keep a very close eye on him.
I know you don't want your friend hurt but she just doesn't want to listen to reason. if Tony hurts her than you have full rights to hurting him. What kind of changes does LS said he has changed?
its good to hear that he is changing but i still suggest that you keep an eye out for your friend just in case.