There's a lot of content here, and replying to old posts is encouraged, so I think there should be plenty of material.

Depends mainly on how we both learn best. For me, when it comes to learning a new language that tends to be finding a well-defined, small (but larger than toy) project and implementing it, and having someone to rubber-duck with (over IM/IRC/email is fine) when I hit conceptual walls. I'm certainly up for tackling something that would help out MIRI.

if some post or comment is confusing to you, don't skip it and leave it to people who might have the right background. Ask for clarifications.

I am hereby publicly committing to doing this at least once per day for the next week.

Modafinil eliminates the feeling of being tired, but not the body's need for sleep. Being in sleep deficit weakens the immune system, and I've seen long-term modafinil use without sleep recovery end in pneumonia. So, if I take modafinil to work on a project or stay alert for a long drive, and I finish before the modafinil wears off, I'll go to sleep anyway, because even if my brain doesn't care whether it gets sleep or not, my body needs it. With stimulants like caffeine, getting to sleep before the stimulant wears off is difficult and leads to less sleep.

Most social-science studies are designed to elicit answers in such a way that the participant doesn't realize what question is actually being asked. For example, when William Labov studied the distribution of rhoticity in spoken English, he asked people innocuous questions whose answers contained the sound /r/ in (phonetic) environments where rhoticity can occur. He'd go into a multi-story department store, look at the map, and ask an employee something along the lines of "Where can I find towels?" so that the person would answer "Those are on the fourth floor." Similarly, the wi-fi study wasn't looking at usability any more than Labov was interested in towels; they were really eliciting "willingness to do something dangerous" as a proxy for (lack of) risk awareness. As long as the measure is wearing unique clothing, participants shouldn't be able to recognize it.

I've TAed a class like the Programming Languages class you described. It was half Haskell, half Prolog. By the end of the semester, most of my students were functionally literate in both languages, but I did not get the impression that the students I later encountered in other classes had internalized the functional or logical/declarative paradigms particularly well -- e.g., I would expect most of them to struggle with Clojure. I'd strongly recommend following up on that class with SICP, as sketerpot suggested, and maybe broadening your experience with Prolog. In a decade of professional software engineering I've only run into a handful of situations where logic programming was the best tool for the job, but knowing how to work in that paradigm made a huge difference, and it's getting more common.

My local hackerspace, and broadly the US and European hacker communities. This is mainly because information security is my primary focus, but I find myself happier interacting with hackers because in general they tend not only to be highly outcome-oriented (i.e., inherently consequentialist), but also pragmatic about it: as the saying goes, there's no arguing with a root shell. (Modulo bikeshedding, but this seems to be more of a failure mode of subgroups that don't strive to avoid that problem.) The hacker community is also where I learned to think of communities in terms of design patterns; it's one of the few groups I've encountered so far that puts effort into that sort of community self-evaluation. Mostly it helps me because it's a place where I feel welcome, where other people see value in the goals I want to achieve and are working toward compatible goals. I'd encourage any instrumental rationalist with an interest in software engineering, and especially security, to visit a hackerspace or attend a hacker conference.

Until recently I was also involved in the "liberation technology" activism community, but ultimately found it toxic and left. I'm still too close to that situation to evaluate it fairly, but a lot of the toxicity had to do with identity politics and status games getting in the way of accomplishing anything of lasting value. (I'm also dissatisfied with the degree to which activism in general fixates on removing existing structures rather than replacing them with better ones, but again, too close to evaluate fairly.)

Also, presuming that the talk Andreas Bogk has proposed for 30c3 is accepted, you'll want to see it -- it's a huge pragmatic leap forward. (I apologize for not being at liberty to go into any more detail than that. The talk will be livestreamed and recorded, FWIW.)

Eh, cryptocurrency has been a thing since the 80s (see Chaum's Blind signatures for untraceable payments, 1983), but it was patent-encumbered for a long time. If you look at the people involved, they're all cypherpunks of one stripe or another, so I'd place cryptocurrency as a subset of hackers at least initially. (The community has certainly expanded since the emergence of bitcoin.)