In reference to the OP, here's what we tried to get the mouse look function to work:
Rebooted the computer, reinstalled the game, new mouse drivers, using a totally different mouse, tried various settings in options related to the mouse as well as keybinds. Nothing at all works. Even using the middle mouse button doesn't work to freely swivel the camera, nor can OP hold down both the right and left mouse buttons to steer the character. The only way to look around is to spin the character using the movement keys. OP is not using any special mouse related software, ie Razer, Logitech, etc.
Using Tequila, btw.