Player rotation with mouse

Go to Steam\steamapps\common\Resident Evil 4\BIO4 (and\or My Documents/My Games/Capcom/RE4/) and open input.ini (and\or usr_input.ini) with Notepad.
Find this block:

###GAMEPLAY

###KEYBOARD

KEY_FORWARD = W
KEY_BACK = S
KEY_RIGHT = D
KEY_LEFT = A

Warning! ###KEYBOARD must be in ###GAMEPLAY category, not in ###MENUS.

Then add:

KEY_RIGHT = MA_RIGHT
KEY_LEFT = MA_LEFT

after

KEY_LEFT = A

You wil get this:

###GAMEPLAY

###KEYBOARD

KEY_FORWARD = W
KEY_BACK = S
KEY_RIGHT = D
KEY_LEFT = A
KEY_RIGHT = MA_RIGHT
KEY_LEFT = MA_LEFT

After that mouse will rotate player, not camera.
P.S. Some times camera can stuck. Just aim and it will fix camera position.