The Romans were not homosexuals. Few in today’s world realize it, but the very concept is one created in the 19th century. For the Greeks and Romans, the sex of one’s sexual partner was of very little interest, what they were interested in was whether one played the active or passive role.
Gibbon was not so much anti-Catholic as he was anti-Christian. It’s been several decades since I read him, but I believe he blamed the Decline and Fall primarily on the rise of Christianity, which I think is more than a little silly. Constantine used the faith as a mechanism to bring the Empire back to life for almost two centuries.
Gibbon’s history criticized the Catholic Church primarily because there weren’t any Protestants around for him to criticize during the period about which he wrote. Also, of course, because there was a lot to validly criticize in the medieval and Renaissance Church. He was even more critical of the Byzantines and Orthodox than of Catholics.
I find the notion that Popes have some sort of special blood relationship with Romans a little odd. Western civilization as a whole owes an enormous debt to the Romans, but I don’t particularly see why the Popes have any more of a claim to Romanity than other western rulers, other than geographically. And of course the later Roman Empire wasn’t really based in the City of Rome at all, which was mostly of historical interest over at least the last two centuries. Roman meant an inhabitant of the Empire, or at least the educated classes, not a citizen of the City. Few of the later Emperors had any particular connection to Rome or Italy.
In 1900 the four most powerful monarchs of the world all carried titles that were variants on Caesar. Two Kaisers, a Tsar, and a Kaisar-i-Hind (Emperor of India). With of course all sorts of small fry with similar pretensions.
I suspect Gibbon knew a great deal more about the primary sources than you do, especially since you seem to be more anxious to defend what you for some obscure reason see as a slur on the honor of the Romans/Catholics.
I think we should keep in mind that apparently just about all the ancient “historians” lied with astonishing freedom. The notion that history is supposed to present an unbiased version of the past is another modern one.
Not that modern historians don’t slant their presentations, they’re just not open about it like the ancients were.