The universe is irrational and infinitely variable, we just happen to have "lucked out" with a repeating digit for the last billion years or so. There was no Big Bang, we're just seeing what's not there through the lens of modern-day "physics". Everything could turn into nuclear fish tomorrow.

alternate history in which electronics and computers never took off

Please, no. The world already has a sickening amount of steampunk.

The high cost of access could well be the point : if you can easily hire a boat to get to your private island, it's pretty simple for governments or peoples to do the same, club you, and take your stuff. A hundred thousand bucks would cover invading you, and make good return on investment.

By contrast, you'd have to have something of very high value to cover a rocket launch, and that something must be mobile enough to send down easily. (Or in extreme cases, you might be the only people who retain full knowledge of the manufacturing necessary to make the rockets, in some way that isn't easy to reverse engineer -- see the difficulty we have reproducing several engine designs as a guide here.)

Such as?

Two standard texts are Easton and Hardy's The Ethical Slut and Taormino's Opening Up.

Person A is an Olympic-level athlete. He can perform amazing physical feats. The limits of his ability can be scored against some sort of metric (lap time, distance jumped, etc.), and since he's working to improve on them, his own personal limits are known to him.

Person B is of average physical fitness.

Person C has a moderate chronic illness. He struggles to perform basic physical feats, but can function independently with some difficulty.

If all three of these people were secretly transplanted into an environment with lower oxygen levels and began to experience mild hypoxia, it seems that Persons A and C would both be more sensitive to this change than Person B. Person A would notice it because he would no longer be able to perform outstanding physical feats to the level he's accustomed to. Person C would notice it because he'd struggle to carry out basic activities.

[Edit for clarity: I'm not saying that Person B would never notice this, but that he would be less sensitive to it, because his performance is higher-variance and subject to less of a "state change", and doesn't have a fine, frequently-scrutinised boundary between what he can and can't do.]

Alternatively:

Person D is a voracious infovore with high reading comprehension. She's used to grappling with precise language.

Person E is an average-level reader.

Person F has some sort of reading-related disability.

It seems that Persons D and F will be more sensitive to badly-punctuated writing than Person E. For example, Person D might be able to parse a sentence in two or three plausible ways, while Person F might not be able to parse the sentence at all.

Both of these cases involve both ends of an ability distribution being more sensitive to degradation of the environment than central cases. Are there better examples? Is this a phenomenon we actually see in the real world? If so, does it have a name?

And... done. I would like to point out that X-Risk question may be confusing when skimming. P(X-Risk) looks as if it were asking for probability of catastrophe coming to pass, but the explanations spells out that the probability of humanity successfully avoiding catastrophe should be entered.

Done. Too bad the basilisk question wasn't on it; I hope that will one day be possible.

I'm a bit confused about the accuracy of my BSRI because my true answer was frequently 'only towards my SO',

Same here. And in some cases it was ‘except towards my parents’ or ‘only when I'm very tired’. I still tried to take some kind of weighed average.

Ooh, missed the announcement. I won't make it in time now. Anyhow, I'll keep it in mind to get in touch with you next time I'm there. Have a blast!