What a strangely singular piece. I loved the textbook excerpts the author created. Actually, I just love it when authors do that, create texts within their universe and show it to us. It gives more background on the universe, how the changes that make the AU affect that universe versus our own, and give great little oblique meta-analyses.
This...is not a romance at all. There's absolutely no romantic interactions between the main characters at all. In fact, I think there being romance in the next one might turn out a bit weird and kitschy. Hopefully it transitions okay.
It's also not BDSM. It's, well, torture. Of the psychological sort, mostly, to be sure, but BDSM? Oh, hell no.
The content itself is fascinating. It definitely skirts the edge between psychoanalysis and questioning/torture really well. The whole concept of the "Eternal Dungeon" is fascinating, definitely very well-constructed.