Quinton, I've shoot over 100 interviews for documentaries on all types of subjects. Your approach is very professional and the right one, but I think you will see as you start to shoot more interviews, that a good location is always your best friend.
You have the basics down pack, I wouldn't stress it much, like I said just make sure you have a good location to shoot and place your subject against a descent background. After a while it becomes natural to the point where I feel conform table showing up to interviews without any lights what so ever and using natural lighting. This is only the case though when I know I'm shooting a great location with a lot of space.