I don't see the manual for this game in my library, and when I went into key bindings in options, what showed there was rather limited.
Is there anything I need to know other than WASD movement, control for crouch, clicking for attacks and Y for chat?
I've only tried the alien, but it mentioned something about vision when I died. Is there a button to activate special vision, or is it just for predators?

you have to use your arrow keys to move down the key binding menu.