1) Yes. The veil network folded layer upon layer of the local space/time around itself (like wrapping a billion quilts around you as you roll over and over in bed) taking it out of phase with normal reality.
When it became unstable the folds collapsed into each other creating a massive tesseract- a 4D object (or energy field in this case) that transcends normal space/time- around the planet.
Inside the tesseract Orisha bounced through those folded layers at random, appearing and reappearing at various points in its own past.
Since Orisha was already present in those periods the introduction of another massive planetary body in such close proximity caused catastrophic destabilization of "both" planets' magnetic and gravitational fields resulting in quakes, weird weather and optical effects, etc. as well as further damage to the veil network. Primitive peoples would, of course, interpret such an event as an apocalypse or the wrath of God.
Even when it was working properly the veil's multiple enormous space folds also destabilized the normal behavior of subatomic particles in the region, creating the expanding disruption wave that mimicked a warp pulse as well as the crunched quantum rippling that "preceded" it.
3) Yes. He was talking to Vale.