@Zeslonatrus there is one, however it was not updated since a couple of months, so I do not recommend to use it as daily driver. Sadly its not possible to be really private in todays connected world. However, what you can do is to disable your WiFi/Mobile Data and GPS if you do not need it.
@Zeslonatrus thats quite difficuilt to answer and thats why so many people are concerned about their data. You can never know, wether your geolocation is requested, your messages or even a screenshot is being taken. Technically all of these are doable and realistic, however you also need to ask yourself what you have to hide. As long as you do not plan a bombing no one will really care.
If you use it as a company phone:
I seen an interesting documentation about chinese companies trying to hack german ones with the deal to collect data. Since then that one company moved back to “offline communication”. Additionally it was forbidden for them to use random USB sticks (quite common though).