Cannot turn on Bluetooth - Exhausted all options
Try resetting the NVRAM. After all else failed this worked for me.
https://support.apple.com/kb/HT204063

Option key + Command key + P key + R key
Shut down your Mac, then turn it on and immediately press and hold these four keys together: Option, Command, P, and R. You can release the keys after about 20 seconds, during which your Mac might appear to restart.
When your Mac finishes starting up, you might want to open System Preferences and adjust any settings that were reset, such as sound volume, display resolution, startup disk selection, or time zone.