Finally I found the correct tool and correct way to fix all (almost) the camera problems!
1, Aiming mechanic changed. There are not dead angle any more when aiming left side, because the whole body will move.
2, Smoother camera control, and the camera will not go through the wall. (Most situations. If too fast it will still go through) It will shrink the distance like many other 3rd person games.
3, If you are using mouse keyboard, the mouse control is much better.
4, Camera FOV increased a little.
5，Critical stab mechanic changed, it will delay a little bit, makes more tense. Just follow the hint you will make it.
6, Footstep sound added.