I am kind of suprised you didn't reference causal inference here to just gesture at the task in which we "figure out which variables are directly relevant - i.e. which variables mediate the influence of everything else". Are you pointing to a different sort of idea/do you not feel causal inference is adequate for describing this task?

Also, scenario 1 and 2 seem fairly close to the "linear" and "non-linear" models of innovation Jason Crawford described in his talk "The Non-Linear Model of Innovation." To be honest, I prefered his description of the models. Though he didn't cover how miraculous it is that somehow the model can work. That, to a good approximation, the universe is simple and local.

Hymn to breaking strain or Hope Eyrie.

Here's a visualisation that goes along with Euclid's elements

This was one of many from an article on "The Empirical MetaMathematics of Euclid and Beyond". It is a long essay on the overarching structure of Euclid's elements and verifies some claims made about Euclid's Elements e.g. the proofs were ordered in nearly the most parsimonious way possible. It also finds the most difficult theorems in each book, the greatest possible reductions in proof length, and hints that the network of theorem dependancy has a local 2-d structure. Highly recommend the article. 

Definetely not a subject, but I'd say that the visualisation of Wolfram's theory of everything is excellent. Of course there are problems with his theory of everything, like the fact that he hasn't actually proved his claims that it generates GR field equations or replicates QM. Or shown that his theory evades the critical objection Scott Aaronson raised. but as a visualisation:

1. It is aesthetically pleasing
2. Compactly contains the basic ideas of his T.o.E. 
3. Ties the basic concepts together to see how they could generate a theory of physics

So I'd still recommend it. 

I am glad you put the quotation marks around "morality as taxes" since what my mind jumped to upon verbalising the title was what you described in the last part of your post: something you'd be glad to evade where possible. In retrospect, its clear that the quotation marks were meant to point to another approach and not the one your thought experiment is meant to represent. Still, I think "Wholehearted choices vs morality as taxes" would be a little clearer as a title. 

My personal reasons:

1. I assumed the question was about the first few decades after "first contact".
2. A large chunk of my probability mass is on first contact being unintentional, and something neither side can do much about. Or perhaps one "side" is unaware of it. Like if we receive some message directed to no one in particular, or recording the remnants of some extreme cosmic event that seems mighty unatural. 
3. It feels like we're near certain to have created an AGI by then. I am unsure enough about the long term time scales of AGI improvement, and their limits, that I can assign some credence to the AGI we make possessing relatively advanced technology. And so, it may be in a good bargainning position. If we make plenty of AI, maybe they'll be less powerful individually, but they should still be quite potent in the face of a superior adversary.

You should alter questions to make it clear "we" is meant to be humans or whatever we makes that succeeds us.

Also, perhaps a queston on whether "first contact" will be us detecting them without their being aware of it.

Minor quibble which I hope isn't breaking a norm: BetFair did seem to pay out last week, or at least some of the bets on who would win the presidency were settled on 07/11/20. 

Do you expect we'll be n the midst of a third wave before the vaccine begins to be doled out? Or just beginning to enter one? 

Thanks for the post.