Have a Blessd Advent, O.P.
Re the First Epistle of St. Peter; "For St. Peter's residence and death in Rome there is solid evidence that goes back to the end of the 1st century. This is admitted by A. Harnack, Chronologie der altchristl. Literatur, I, 2403, 703-10,: H. Lietzmann, Petrus and Paulus in Rom, Berlin, 1927, 226-38 : F.J. Jackson, Evidence for the martyrdom of Peter and Paul in Rome, JBL 46 (1927) 74-8; cf. Holzmeister, 37-71. Hence, when the Apostle concludes with :...The church that is in babylon..saluteth you," 5:13, we may be reasonably presume that 'Babylon' here, as in Apoc. 14:8; 16,19;17:5; 18:2,10,21 refers to Rome as the palce of composition. This was held by Papias and Clement of Alexanderia, according to Eusebius, Ecclesiastical History 2,15; cf, also St. Jerome, De Vir. Illust 8, PL 23, 622.
From "A Catholic Commentary on Holy Scripture" Thomas Nelson and Sons LTD, 1953, edited by Dom Orchard (General Editor and New Testament Editor)
"By Babylon, as observed before, may very probably be signified all the wicked world in general, whom God will punish and destroy after the short time of this mortal life; or may be signified every great city, and perhaps Rome returned to idolatry in the time of the antichrist, a little before the end of the world; or may be signified the idolatry of heathen Rome, in the fourth age, when the Christian religion, under Constantine and his successors, began to triumph over paganism, i.e. according to those interpreters followed by Alcazar, Bousset, P. Alleman ect. It is probable that here by the great Babylon is meant the city of the devil; that is, the universal society of the wicked; as Jerusalem is taken for the city and Church of God." The Haydock Version of Douay Bible and Rheims Testament.
The language of the Apocalypse is so highly symbolic and open to different levels of meaning and has been understood differently by so many orthodox Christians that it prolly isn't wise to be so circumspect or dogmatic or pedantic as to strictly interpret Babylon as meaning "just" this or that city/place. Babylon can be understood as to applying to different events/cities/times