Everything else is just a matter of the efficiency or difficulty of how you get the heat to that point..
It reduces the thermal resistance between the chip and the heat sink, so for a given installation and heat rejection rate the chip itself will be cooler.
You do not add any weight to an aircraft that isn't absolutely necessary and you do not add any kind of active device where a passive one could work because of reliability. Keeping electronics cool in an aircraft is a very complex and expensive problem. Keeping a chip even two or three degrees cooler will have a measurable effect on the reliability over the aircraft life.
When a friend of mine decided to take the Arbitur exam here in Germany (A kind of high school graduation level) as an adult I volunteered to help her with the maths and promised her I would show her the beauty of it and she would learn to love it.
I failed dismally because the maths she had to study was all the really dull stuff I had forgotten about: solving triangles, calculating probabilities, quadratic equations... I realised that maths only really becomes beautiful when you get to calculus; before this it's just drudgery.
security (the potential for terrorist damage is much smaller considering you can't fly one arbitrarily into a building)
I think you have this the wrong way around. The only drawback I can see with Elon's Hyperloop is it's susceptibility to terrorism; you need to keep airport-level vigilance over its entire track length, that's a lot of razor wire, dogs and operatives.
Sadly, you started exporting the same coffee back to us and now they put cup holders in our cars too.
The US planes may be better in many respects.
On what grounds? From a technological point of view there is little to choose between Airbus and Boing planes of a similar generation and duty. Which one gets chosen depends on the financing deal offered and not much else.
Most notably it killed the house robot 'Matilda.
'It also used a self-righting mechanism that served a secondary purpose of enabling it to take a bow at the end of the battle. Very cool.
Give a man a fish, and you feed him for a day. Teach a man to fish, and he'll invite himself over for dinner. - Calvin Keegan