It should be a relatively simple task, just somewhat
time consuming.
Let me know if you are still interested and I will point out the source
code that needs to be changed.
This is only regarding kdebluetooth but what about kmobiletools?
I don't know. My guess is that once kdebluetooth is fixed applications
that depended on it (such as kmobiletools) can be reactivated. I am not
confident on this however, not having looked at the source code myself.
In KDE:KDE3 kmobiletools does not depend on kdebluetooth. It builds
well with the modern bluez. Kdebluetooth indeed requires older bluez.