I didn't read this whole thing, but lost soul, this is the most serious response I can come up with.
You're going to get yourself killed.
Can you get your hands on a bullet proof vest? Will these gadgets of yours really work? Will you have enough ammunition? If you train yourself, how do you know that you're not fighting somebody who trained harder than you did? Can you fight multiple people at once? If you beat up a bunch of thugs and make your escape, how do you know one of them won't be following you home? If you're acrobatic, how do you know you won't be so hurt that you can't perform those amazing stunts? Just because you survived a shot to the leg, does that mean you can take one to the kidney, spine, chest, or head? What if you inspire some copycat and that person gets themselves killed? What if the police hunt you down? What if the FBI hunts you down? What if you put your loved ones in danger? If someone kidnaps your girlfriend and (God forbid) hurls her off a bridge, can you catch her? What if someone snatches off your mask? How will you have a social life? What if you lose everyone and everything you hold dear in life?
On a final note, if we ever hear about a vigilante running around in L.A. it won't be hard for Mirko to trace the IP adress that you posted this on and then it'd be very easy to find you.
If you wanna help people, why not become a cop, fireman, social worker, or (non-crooked) politician?