Nantucket and The Time Patrol

If the Nantucket Event had occurred in the Time Patrol timeline, then the Patrol would have prevented the Nantucketers from changing history but would also have returned them, if not also their island, home. But the Patrol would also have had to discover the cause of the Event. If random quantum fluctuations in space-time-energy can change history without human intervention, can they also cause time travel without benefit of technology? In fact, is the entire universe a single particle traveling backwards and forwards in time? If so, then it is a different kind of time travel:

a Time Patrol vehicle disappears from one set of spatiotemporal coordinates and appears at another without existing at every intervening space-time point;

Nantucket traveled in this way;

Wells' Time Traveler on his Time Machine and Anderson's Jack Havig exercising his psychic power do exist in the same position on the Earth's surface at every moment between departure and arrival;

the anakro in Anderson's The Dancer From Atlantis follows a great circle on the Earth's surface while moving backward in time;

Anderson's Wardens and Rangers walk or drive along their time corridors; 

spaceships flying around T-machines make long interstellar space journeys as well as time journeys;

both the time projector in Anderson's "Flight to Forever" and Doctor Who's TARDIS exist in something like hperspace (or hypertime?) between departure and arrival;

in fact, the Doctor refers to "the Time Vortex."

So how many kinds of time travel are there?