I don't know much about socionics. Could you briefly explain the general difference between it and MBTI? Interesting read, but I'm afraid I'm not quite understanding it. I identify with distant and initial, but according to this, it means that I must also be connecting (H subtype). Why can I not be ignoring instead? With 3 scales, there should be a total of 6 subtypes, not 4.

The primary difference is that socionics is more about intertype, how people interact with each other. There are other theoretical differences e.g. socionics structures the types a little differently but I say that they are, by and large, the same based off Jung's original observations. They just went and did it differently.

As for the way the DCNH is structured, it has to do with that it's the internal logic of the system. Ti doms lol. I do find though, that once you figure out your subtype, it's actually accurate. It's also going off the Reinin dichotomies that are partially based off the original Jungian dichotomies but add behavioral differences between the types. You can google about Reinin as it's too much to go into here.

What I like about the interaction styles is that they are more useful than Kiersey's temperaments because they are more readily observable.

Yeah, I agree, in a sense. DCNH, as you can see here, actually describes why some people get along with others and why they don't. Again, because this is the main focus of socionics. Socionics has a similar system to Keirsey's temperaments called clubs, but they are more about focus of interest i.e. NTs like theory, obviously. The difference is that socionics does it as NT, SF, NF and ST, as opposed to SP and SJ.

This is a rather bold claim. Care to point me to some documentation?

Viktor Gulenko alludes to this in the article. I unfortunately do not have access to it as most information about the theory is in Russian. I'm quite sure that if you check Viktor Gulenko's blog, you may be able to find something, though.