The fundamental fact that led Einstein to special relativity is that light in a vacuum appears to be traveling at c regardless of the observer’s frame of reference.
If the observer is a photon, however, it must be able to observe a photon traveling at 0 m/s relatice to it (is, the photon itself). This removes the cornerstone of special relativity and the whole thing comes apart. Using it to make predictions at this point is pointless.
There may be a way to describe the perspective of a photon - we haven’t discovered all of physics yet - but none of our current theories do so.
> How long does it take to to planet A on the travelers watch.
You're the one who discovered magic; the answer to this question depends completely on how magic works.
But without magic, it is impossible for an object with mass to accelerate to c. Why do you believe the question has an answer?
The answer is that the distance from A to B would be length-contracted, and would take (from the traveller's point of view) very little time to traverse. In the limit, once the traveller has reached the speed of light, the entire universe in front of them contracts to zero length, and they (from their point of view) can cross the entire universe in no time. Like a photon, they would experience no time between achieving the speed of light, and hitting something.
From the point of view of planet A and B, it still takes a whole year for the traveller to make the journey.
This is like saying that if you put two protons in exactly the same place they would repel each other with infinite Coulombic force.
How long does it take to to planet A on the travelers watch. No copping out and saying they've been destroyed by inertia.
I am going to assume it takes one year and and one minute-ish compared to synced clocks in the AB pair.