1. Import tickets from spreadsheetYou would need to talk to the folks over at: http://osticket.com/professional-installationto see if they have something like that. I do not believe that there is a free (public) way to do that.2. Automatically adding ticket to calendar, google calendar preferred. or exchange calendar.
Again I dont know of a plugin that does that, but I imagine it could be as simple as adding a way to have an email sent in the format that Outlook or Google wants to see it in so you can add it.
3. Allowing customer or organization to have basically a private notes, that we can't see. it just seen by the organization staffNo one has ever requested such a feature before, and really anyone with access to the DB would be able to see it anyway. Or if it was encrypted in the DB they would be able to reverse engineer and decrypt it if they were really determined.4. Allowing specific organization user to change ticket status. I strong beleive that customers should not dictate ticket state. The only exception to this is that they should be able to re-open a recently closed ticket if that ticket was not resolved. Which they can already do by replying to the ticket 5. mobile app to access osticket. i saw some on the play store but none worked. There is no official mobile app for osTicket. But then really you can access it from any cell phones web broswer so I personally don't see the need for one. If these are things that you really really need and are willing to pay for them I would recommend that you contact the folks over at: Customization Services.http://osticket.com/customizationI have no idea what they charge, but money goes toward keeping this project alive. If they can't help you then there is always the option of Freelancer etc, or doing it yourself.I feel like these aren't really the answers that you were hoping for, but hopefully I've pointed you in the right directions.