Are there settings that I should change in the sandboxed google play settings for better privacy?
It depends on what you are trying to achieve.
Think about it, and than you will know the answer.
It depends even how you use your phone, what apps do you install. Or you can even compromise perfectly setup phone with PIN 1234.
314random that makes sense. I just thought there was a "rule of thumb" that people do when the install play store