An open letter to Miley Cyrus from me would go something like this.
Frankly, I'm worried about you and I really think you need counseling.
When you were young, 'Hannah Montana' was a huge hit show for you and it was fun to watch. It was a nice family show and good to see your real dad and godmother acting alongside you.
Then you grew up and needed to shake the whole 'Hannah' persona, I get that, I really do. However, was there really any need to turn into a semi porn star in the process?
It seems your main aim now is not to make music, but to shock. Your dad is a lovely man and he stands by you, what a gentleman. Yet he must be deeply hurt by the way you are behaving, and I would think that Dolly Parton isn't exactly proud to call you her God daughter right now either.
At the moment Miley, you are just a joke. Everyone just laughs at, and pities, you.
Do something about it before it is too late. If this is you being grown up I would hate to see your idea of a complete career train wreck.
The sad part is, Hannah Montana was a much nicer person and she didn't actually exist!
Get help, become an adult and try to save the career that you are killing more and more each day.
That's all :-)