In regards as to whether the mini-suites balconies are totally private or not, I can't be of much help. I will say that my wife prefers to have the balcony open at the top so she can get some sun.
You can book your shore excursions online. You will need to have your booking ID number, in order to log in.
You can pre-reserve your shore excursions after you have logged into the url above. Princess suggests that you have the printed Shore Excursion brochure you received with your cruise documents and your passport handy to use as a reference.
Hope this helps: