ISTM that you can't pick up hydrogen along the way unless you're moving as close to the same speed as the local drift.
OTOH, fusion does promise a lot more power/kg. whether it can deliver that in a controlled manner, however, may be another question.

I don't consider that a "kind and gentle" response, but if he described the code accurately, it does seem warranted.

If I parsed that correctly it was the eggs that were green, not the ham.

If it's made out of mushrooms, it's not coffee. OTOH, mushroom flavored coffee might be quite good...it would really depend on both the coffee and the mushroom.

By the time we can build that, we'll be using asteroids and small moons for raw materials.

Genetics is important, but "chaos" is equally important. Development has lots of attractors where really small initial differences yield extremely different results. OTOH, most chaotic developments are bounded in their differences. So you may not be able to predict individual differences, but can do better at the population level.

2400 people is enough that nobody there would know everyone else. That's probably important. OTOH, we don't know anything about designing stable societies in an environment with rapid technological change and fast communications. The only stable societies that we have record of have been low-tech with minimal contact with outsiders. Even those have often been brittle under stress, but much of the population has been able to survive collapse and rebuild.

Yeah, but 400 years is a bit longer. They'd need a different reactor design. Perhaps one that works on waste from the current reactors, but they might need to take along (or build en-route) mechanisms to refine the waste again as it kept decaying.

(N.B.: I didn't even THINK about doing the math, but reactors that require high level radioactive fuel won't keep running long enough, but one's that use less active fuels could. Of course, they'd be a lot larger. If you're going to use an RTG, and you want it designed for this purpose, I think you'd want to design it for a fuel that had a half life of 800 years. So it would need to be a lot bigger for the same amount of power.)

Ungh...if the answers are available to be read, it's not a particularly good test of much besides the ability to read

That's *not* a valid argument, though it is a real danger.

An AI cannot invent it's "primary goals" any more than people can. It can only invent secondary goals, instrumental goals, etc. Which of those it invents will depend upon both how intelligent it is and what it's primary goals are.

However, it is an unfortunate problem that most obvious sets of "primary goals" are dangerous. And most people are trying to build slaves rather than friends.

There's two ways to parse the GP's claim, i.e.
"You could literally spend the rest of your life trying to answer a single question from that exam"
1) All of the questions are insanely difficult.
2) At least one of the questions is insanely difficult.
You have clearly picked the first parse, but I strongly suspect he meant the second parse.

Also 3 and 5.