The MR rules thing is interesting - but if I've read Dr Drib's posts correctly, it seems the moderators might not have too much of a problem with us if we always restrict ourselves to only discussing the works intended for the anthology. (I'm sure I will be corrected if I have misinterpreted.
) Yes, there is an element of self-promotion in that, but the risk for authors taking part is that there may also be an element of self-denigration (after all, others may be criticising the work online in this forum).
As for the stated purpose of this subforum, it could be argued that there is no better way to discuss the "art, craft and business of writing and (self-)publishing" than actually going through the process right here in the open where everyone can see what's involved.
Yes, any discussion of the details of a particular work will necessarily contain spoilers. If we have a thread for that then the subject can including a big "CONTAINS SPOILERS" warning, and/or spoiler detail can be put in spoiler tags (but that could start to make the discussion more difficult to follow).