It is not in principle insane.
The atmosphere contains a large amount of very light gas, and plutos mass is low.
This means that the atmosphere is quite 'puffed up' - meaning you can skim the planet and get quite a decent brake.
The required large aerosurface due to the low density makes it 'interesting'.
It requires detailed knowledge of the atmosphere.

"If any exoplanets were outweighed by something else in the same orbit, we would have detected that other thing first"

This is not correct in many cases.
For example, for Kepler - planets are found by looking at the dimming star as the planet comes in front of the sun.
If Kepler detects a planet, it is entirely insensitive to small objects in the same orbit, even if there are a _LOT_ of them.
It is also insensitive to objects outside the plane of the system (apart from timing transit variation for really large bodies)

Similarly - radial velocity is going to be entirely insensitive to multiple small bodies in an orbit.
It's worth noting that Kepler has detected exactly 0 earth-like planets in earth-like orbits around sun-like stars.
There are lots of holes in the data due to insufficient signal-noise.

"has cleared"
This is at best debatable.

https://www.youtube.com/watch?...
Makes the case that saturn and jupiter cleared earths orbit of 'hot jupiters' as they migrated in, causing collisional cascades and the remnants of those condensed into the terrestrial planets.

Pluto as a planet doesn't really make much sense, without including others.
Eris, for example. While currently three times the distance of pluto from the sun, at times (next ~2800AD) it is actually closer than pluto to the sun, as well as more massive.
There is no real inarguable set.

The problem is that you pretty much can't pick another.
The trajectory chosen was to reduce mission time.
If you have 9 years, then pretty much the only way you can do a pluto probe is blasting past at >10km/s.

If you try to make the trajectory more gentle, then yes, you can do this - a hohmann transfer - but this will take literally a hundred years. There is nothing close to pluto that can slow you down meaningfully at all with a gravitational assist.

Nuclear powered ion engines, nuclear rockets (dusty fission rocket), and aerobraking are all in principle possible, but they all have their own risks.

Well, yes, everyone knows that would be awesome.
Some rough numbers I did indicate that to stop New Horizons (It is only 400kg) at pluto would take a Delta V heavy. That is - around 500 tons.
A launch campaign to launch 500 tons to pluto is likely to need several thousand rockets.
Stopping is hard.

NASA is _terrible_ at designing rockets.
They do it at great expense and time.
http://www.nasa.gov/pdf/586023...

Page 9 - Spacex tool ~440M to develop falcon 9. A more typical NASA approach might take 1.4 billion.

Likely well north of half a billion.

No, really, this isn't someone that's just stolen their bag at an airport.

I was more meaning the circumstances - just because you find a GPLV2 'Copying' file in the file-tree does not mean that the whole thing can be distributed, as you have no way of knowing what the authors intent was.
If I put a COPYING file in my windows source tree, it doesn't make windows open-source unless I have the authority, legal clearance, and intent to release that code.

I can't find details of exactly what licence, and how this aspect was found not relevant.

Especially if computers are not your life, but something you want to - say - weekly - write letters on.
Once you drop the frequency you're doing something, learning gets lots harder, even for the young.

'without cognitive impairment'.
'cognitive impairment' is a hell of a lot more gradual than you think.

For someone using computers a lot, they're probably going to figure it out.
For someone not using computers a lot, and who have managed to do things by remembering exactly what to click - this is enormously fragile.
Issues from 'I might break it' -> 'I might put it in a mode I don't understand how to get out of'

Someone in this position may not be able to recover from an expanded list collapsing down to a tiny triangle on a mis-click, especially if this is a feature that they will never need.
Or icons changing from ones they know, or menus moving around.

This article was brought to you by the makers of quality monitors, that are all you need, and do not cause your brain to melt like goggles do.

That would rely on the steel being magnetised, and repeling the board.
If the superconductors are simple magnets, then all that happens is you have a big clang as it clamps onto the surface.