Like the title suggests, I think that adding the option to tilt the camera left and right just like how you can tilt it up and down would be a really neat addition, especially for people who like to take a lot of screenshots in-game (*cough cough* like myself) since being able to decentralize your character can really help with compositions a lot of times.

The day I started playing the game I was amazed at how complete, well made and detailed almost every aspect of it was, which was the reason that left me so surprised over the fact that there is no left/right camera tilting (while some other not-so-detailed MMOs actually have it, like Tera or Blade and Soul to name a couple.)