I have a question, will be possible in the final game to look to the left and the right without rotate your whole body? Take a quick look to the sides could be important during a first person combat situation. Maybe like it is done in Flashpoint or the Arma series (Ask Viktor about it, he will know). Or make it more quick, “Q” look to the left, “E” look to the right. And if you release the key the vision is again on a focus straight to the front.
Edit:
@TobiTobsen, what does the Devteam say about this idea? It don´t should be too difficult to implement but should have a huge adventage in first person combat.