WIDCOMM bluetooth (works on TP2. If these do not exist it may because of the ROM you are using):
HKLM\SOFTWARE\WIDCOMM\BTConfig\Devices
HKLM\SOFTWARE\WIDCOMM\Connections
Restores headsets, as well as PC/laptop connections, etc. I've tried these, and managed to restore my headset, plus my ActiveSync and FileTransfer BT to my laptop
Thanks to
mrmediaguy.
And you can backup/restore your BT discoverable device name using this one:
HKEY_LOCAL_MACHINE\SOFTWARE\WIDCOMM\BTConfig\Gener al
"DeviceName"="device_name_here"