@Tau Discussion
Thanks, guys. I knew that a Star Trek analogy would clear up confusion.
The thought has occured to me that I may have been advocating two seemingly-contradictory positions in this thread and a previous discussion- here, I've been arguing that biology-plus-culture often play a dominant role in determining aptitude and enthusiasm for a given set of behaviours, whereas before I was arguing that even individuals subjected to both intense biological and cultural conditioning (e.g, a Space Marine) may nonetheless defy those inclinations.
I guess I can only concede that (A) there probably are going to be members of Tau society that buck the averages for their caste, and it's not clear how well, if at all, their needs are accomodated, and (B), in the case of a Space Marine, it's possible some choices are only psychologically plausible under intense counterposing stresses. (Though I did outline those.)
I don't have an easy answer to those questions. But I would have to consider them the least of several evils. So I, for one, welcome our blue-grey overlords!
EDIT: I also think it's quite possible that the relative lack of specialisation among humans will actually turn out to be a significant asset to the Greater Good (tm). There are, after all, significant benefits to be had from cross-disciplinary studies and 'out of the box' thinking, for which reason human auxiliaries have been well-regarded on the battlefield. I would be very interested to see what happens when/if humans begin making corresponding inroads in the fields of tau aesthetics, commerce and industry.
Oops. Missed this one. As I argued earlier, while hive/forge worlds may be a minority of the planets in the imperium, if you assume anything resembling a plausible housing density they probably constitute the great bulk of it's population.
Worlds in the imperium are allowed to be nice to the exact extent that they're not really imperium worlds- which is to say, it's hard for the imperium to directly administer them, such as in Ultramar, and/or on border/feral/feudal/pre-spacefaring worlds, and/or because they serve as private playgrounds for a tiny fraction of the super-rich.