Your two points.

Your first point is, of course, true (that masculinity is defined differently from place to place and in the ancient world being a penetratee was by definition non-masculine). So, yeah, the Romans would have had a hard time conceiving of any way in which a boy could in indulge in homo-sex that wasn't compromising to his masculinity. My understanding is that the earlier Greeks got around this by eschewing anal sex and instead indulging in intra-crural (and the boy wasn't supposed to "enjoy" it but to put up with it as a form of gratitude for the other aspects of the relationship.) (Interestingly, according to the two books I have read on historical Japanese pderasty -- Plughdelder's and Gary Leupp's Male Colors -- not only was anal sex not thought of as not compromising your masculinity -- as long as you were the passive partner when you were a boy, not a man -- but that it was hardly considered "real sex" unless anal was involved -- oral sex was thought of as somehow disgusting.) As for your second point, the appearance of visible trannies outside strictly defined roles (berdache/katoey) is, if I understand Paglia correctly, a phenomenon of decadent societies. I may be guilty of misrepresenting her views, but I believe she means by decadence not simply plutocratic excess (although that is one sign) but also an erosion of traditional gender roles (traditional as that society defined them), widespread mocking of the given society's traditional virtues, the turning away from personal risk in defending the society by any who can afford it (e.g., the Romans hiring barbarians to defend the empire; the last US president to serve in the military was George H.W. Bush and no member of America's ruling class today serves in the military). I suppose she was channeling Spengler and beyond him Nietzsche. Of course it is easy in retrospect to label late antiquity "decadent" since it collapsed shortly afterwards (why we call it "late" antiquity) but it certainly had all the signs: plutocrats given to excess, volatile urban mobs, the avoidance of military service by anyone who could, the collapse and open mockery of traditional virtues, the rise of all kinds of competing new religions and ideologies, and a decline in traditional sex roles with a lot of gender bending. Of course all this is going on today too. SR