Thanks for all the info!
If it helps, take a look at my Controller Plugin and Camera 3D Plugin. I use them together with my Character 3D Plugin to support mouse/keyboard and controller out of the box. Along with providing an image for every key/button for use in your UI that tracks the last thing the player used as a controller. (You can see that last part in my current game if you open the Controls window in the upper right of the HUD.) They support multiple camera angles including first person, third person follow, Isometric, birds-eye view, etc. Allowing the player to scroll through them. Feel free to use the plugins or grab the code that helps your implementation.
The main difference between the two is when you're using a mouse you have to reset the look variable every frame, and with the gamepad you have to let the value accumulate.