In the Sequence, Eliezer made a strong case for the realist interpretation of QM (neo-Everettian many worlds), based on decoherence and Occam's razor. He then, in another point of the Sequence, tied that problem with interesting questions about anthropic probability (the infamous anthropic trilemma), and that cemented MWI as the preferred way to think about QM here.

On the other hand, I think we are still missing the big picture about quantum mechanics: ER = EPR, categorical quantum mechanics, QBism etc. all points us to interesting unexplored directions.

Only in very extreme case. Have you looked up on every alternatives?

The problem with depression is that it skews your entire ability to think clearly and rationally about the future. You're no longer "a rational agent", but "a depressed agent", and it's really bad.
From an outside view, of course only very extreme pain or the certainty of inevitable decline are worth the catastrophic cost of death, but from the pov of a depressed person, all future is bad, black and meaningless, and death seems often the natural way up.

From the page you link:

The T predicate is primitive recursive in the sense that there is a primitive recursive function that, given inputs for the predicate, correctly determine the truth value of the predicate on those inputs.

Also from the same page:

This states there exists a primitive recursive function U such that a function f of one integer

The standard notion of a UTM takes a representation of a program, and interprets it

Nope. The standard notion of a UTM take the representation of a program and an input, and interprets it. With the caveat that those representations terminate!

What you say, that the number given to the UTM is the number of steps for which the machine must run, is not what is asserted by Kleene's theorem, which is about functions of natural numbers: the T relation checks, primitive recursively, the encoding of a program and of an input, which is then fed to the universal interpreter.
You do not say to a Turing machine for how much steps you need to run, because once a function is defined on an input, it will run and then stop. The fact that some partial recursive function is undefined for some input is accounted by the unbounded search, but this term is not part of the U or the T function.
The Kleene equivalence needs, as you say, unbounded search, but if the T checks, it means that x is the encoding of e and n (a program and its input), and that the function will terminate on that input. No need to say for how much steps to run the function.

Indeed, this is true of and evident in any programming language: you give to the interpreter the program and the input, not the number of steps.

That's interesting, you think of yourself as an aspiring villain? What does that entail?

Because primitive recursion is quite easy, and so it is quite easy to get a universal Turing machine. Filling that machine with a useful program is another thing entirely, but that's why we have evolution and programmers...

Yes, but the U() and the T() are primitive recursive. Unbounded search is necessary to get the encoding of the program, but not to execute it, that's why I said "if an angel gives you the encoding".

The normal form theorem indeed says that any partial recursive function is equivalent to two primitive recursive functions / relations, namely U and T, and one application of unbounded search.

This is awesome, thank you!