What Kernel extensions should be deleted to disable bluetooth?
I'll leave this open to a more definitive answer, but after some guess-and-check I was able to disable the Bluetooth preferences pane with an error To see this preferences pane, you may need to connect a device to your computer. by removing the /System/Library/Extensions/IOBluetoothFamily.kext file.

Clarification as to which of the following found kernel extensions are specifically responsible for Bluetooth IO would be appreciated:

$ ls /System/Library/Extensions/*lue*
/System/Library/Extensions/AppleBluetoothDebug.kext:
Contents

/System/Library/Extensions/AppleBluetoothDebugService.kext:
Contents

/System/Library/Extensions/AppleBluetoothModule.kext:
Contents

/System/Library/Extensions/AppleBluetoothMultitouch.kext:
Contents

/System/Library/Extensions/AppleBluetoothRemote.kext:
Contents

/System/Library/Extensions/AppleMIDIBluetoothDriver.plugin:
Contents

/System/Library/Extensions/IOBluetoothFamily.kext:
Contents

/System/Library/Extensions/IOBluetoothHIDDriver.kext:
Contents