I wholeheartedly agree!
Regarding the flickers in Neptune’s orbit, the problem has been solved at least three times. The first solution involved taking corrected masses for Jupiter and Saturn into account. That one didn’t really catch on. The second solution was to throw out the anomalous data basically by saying that the observations were botched, and assume there was no problem with the ephemeris of Neptune. That one didn’t catch on either. The third solution (which has caught on, at least for now) has to do with the corrections to the masses of Neptune and Uranus made possible by various probes which flew close to each planet on the way through. Neptune’s smaller, but Uranus is less dense and less massive.
There are still those dissatisfied with the solution, and although this generation’s search for TNOs hasn’t had anything to do with a search for Planet X, the large objects discovered by Brown et al have all been a bit cockeyed and point to some kind of large unknown body in the outer Solar System. Two major champions of the classic Planet X search have passed on, but the search has passed down to a new generation.
My wild uneducated guess is, large objects beyond Pluto will be retrograde (and diagnostic of capture), which is the same situation seen with the dozens of small moons of Jupiter discovered in the past ten years or so.
By retrograde, I will also claim objects orbiting the Sun well out of the plane of the ecliptic. A large body crossing what we consider the ecliptic nearly perpendicularly could have passed near enough to Neptune to yield the anomalous observations and for a short enough period of time.
I know there have been very, very few rotations of the outer planets since they were discovered ... But would a single pass explain the change as first seen?
Once started, a “ripple” in Neptune’s orbit would continue all the way through the remaining passes of every orbit due to inertia. A satellite orbiting earth, for example, once bumped by a comet or second satellite or the Space Shuttle when it was serviced, will continue orbiting, but the sideways motion of that first bump would change each subsequent orbit.