Whenever i get into a fire fight, and the left stick is pressed down (not the right stick) while firing.
It does a melee attack and won't let me fire while ADS.

Just to clarify, i'm not pressing the right stick down.

My problem with melee is that whenever someone melees you they lock on with auto aim and automatically kill you when you are pumping them full of lead

I have it when I do a Stealth Kill out of Cloaking I can't hit anybody, shoot anybody or do anything "Aggressive." All I can do is run around with my powers like a sitting duck.