Sexto Vario Avito Basiano
Alright. Seems like that's Elagabulus. Admittedly he is one of the emperors I know pretty little about so I will have to read more about him. I don't recall any mention of him being transsexual but he does appear to have been one of the more debauched and openly homosexual of the Roman emperors. I still want to stress that our concept of homosexuality and that of the ancient Romans are very different from each other. Roman views of masculinity stressed dominance over others and being the "top" in a homosexual relationship was not seen as weak, emasculating, or "wrong" in the same way homosexuality in general has been traditionally associated in Christian Western culture. To the Romans if you were the one doing the fucking then it mostly didn't matter who you were fucking. Exceptions included freeborn children, other men's spouses, and certain religious figures. Additionally, as long as your sexual activities did not interfere with your civil obligations or your management of your family life they were mostly left alone. In Elagabulus' case his debauchery was interfering with his governance of the Empire and he also appeared to favor his lovers in the distribution of high-ranking political positions and appointments, earning him many political enemies and rivals.
It's difficult to compare the pre-Christian Romans with the Christianized Romans in this way because of the significant differences between their views on this subject and others. Likewise it is also not always fair to compare the Roman Republic-eras to the Empire's different periods. Rome was not a monolithic, unchanging society and culture; their cultural norms and mores changed and evolved over time. Even my own previous statements are significantly generalizing and simplifying their views on homosexuality for the sake of argument.
I guess what I am trying to say is that it's hard to compare different peoples from different cultures with different moralities. These kinds of comparisons - especially ones done over potentially many millennia of time - are always going to lead to contradictions and conflicts of morality.
I do agree with your assertion that the Roman Empire became the Catholic Church, at least in the spiritual sense. However, politically the Church was never quite able to maintain the level of control over Europe that the Roman Empire did. At many times in the centuries following the collapse of the Roman Empire the loyalty of the various successor states to the Church was nominal at best. Most importantly, the cultural hegemony of Rome was assuredly broken after its demise. People in what is now France or Spain, for example, did not view themselves as "Romans" like they did in the past. They viewed themselves as Frankish or Visigothic, or the various succeding cultures of those peoples. This errosion of Roman culture can be seen in the divergance of languages and cultures after Rome's collapse ; whereas before there was a mostly homogenized culture emanating from a central source - the Empire - there were now multiple different cultures emanating from different sources occupying Europe.
Funny enough, most - if not all - of the succeding states in Western Europe after the Fall of the Roman Empire were Germanic in origin and the Germanic peoples did not have the same kinds of views on sexuality - and especially homosexuality - as the Romans before them. I personally think it is a combination of the adoption of the Christian faith with its Abrahamic proscription of homosexuality and the transferance of the cultural origins of these states to Germanic ones from Roman ones which resulted in the seemingly complete reversal of cultural views on homosexuality within Europe.