Short answers, pulled from the story.
The first trans-Neptunian object discovered after Pluto and Charon carries the provisional designation 15760. This body is now named Albion and orbits beyond Neptune without crossing its path.
New Horizons flew by Arrokoth on the 1st of January 2019 at a distance of approximately 3,500 kilometers. This encounter made Arrokoth the smallest object ever visited by a human-made probe.
As of recent counts, 870 objects have perihelion greater than 40 AU and aphelion less than 48 AU. These parameters define the specific boundaries for classical Kuiper belt objects in current surveys.
Cold population cubewanos possess inclinations less than 5 degrees and red surfaces while hot population cubewanos have highly inclined and eccentric orbits with bluish hues. Recent studies using larger datasets suggest a cut-off inclination of 12 degrees separates these two distinct groups.
The Minor Planet Center does not list cubewanos using the same criteria as the Deep Ecliptic Survey. Many TNOs classified as cubewanos by the MPC appear as ScatNear objects under DES rules.