I don't think you you need all of this done.
IMHO... out board bearing and internal/integrated headsets mean no need for facing. To much paint is the only reason to face now jigs and parts are much better now.
As for the "cleaning/preparing" the threads just thread your part in slowly. If there is resistance back it out use a brass (soft) wire brush to clear slivers re-thread use plenty of lube on the treads.
Due the build your self.