Get with a good teacher and take lessons. Keep your head in the sound and always in the sound. And then when your done still keep your head in the sound. The body is a slave to the mind. Have a great sound in your mind and your body will produce that beautiful sound. Yes it is that simple.
Again get with a good teacher. And keep your head in the sound. Don't worry about all that stuff you described that's what lessons are for. And if you keep your head into making a beautiful sound your issues will resolve over practice and time.
Again, yes it is that simple.