I'm kind of curious. Taking into account that our God is a consuming fire, would this statement be offensive to modern Catholic teaching and theologians/apologists? I'm only asking because the main objections being raised are to points that some might be more willing to acknowledge as being just opinion or speculation.
But if souls have departed this life in faith and love, while nevertheless carrying away with themselves certain faults, whether small ones over which they have no repented at all, or great ones for which--even though they have repented over them--they did not undertake to show fruits of repentance: such souls, we believe, must be cleansed from this kind of sins, but not by means of some purgatorial fire or a definite punishment in some place (for this, as we have said, has not at all be handed down to us). But some must be cleansed in the very departure from the body, thanks only to fear, as St. Gregory the Dialogist literally shows; while others must be cleansed after the departure from the body, either while remaining in the same earthly place, before they come to worship God and are honored with the lot of the blessed, or--if their sins were more serious and bind them for a longer duration--they are kept in [hades], but not in order to remain forever in fire and torment, but as it were in prison and confinement under guard.
All such ones, we affirm, are helped by the prayers and Liturgies performed for them, with the cooperation of the Divine goodness and love for mankind. This Divine cooperation immediately disdains and remits some sins, those committed out of human weakness, as Dionysius the Great (the Areopagite) says in 'Reflections on the Mystery of Those Reposed in Faith' (In 'The Ecclesiastical Hierarchy, 7, 7); while other sins, after a certain time, by righteous judgments it either likewise releases and forgives--and that completely--or lightens the responsibility for them until that final judgment. And therefore we see no necessity whatever for any other punishment or for a cleansing fire; for some are cleansed by fear, while others are devoured by gnawings of conscience with more torment than any fire, and still others are cleansed only the the very terror before the Divine Glory and the uncertainty as to what the future will be...
And so, we intreat God and believe to deliver the departed from (eternal torment), and not from any other torment or fire apart from those torments and that fire which have been proclaimed to be forever. And that, moreover, the souls of the departed are delivered by prayers from confinement in [hades], as if from a certain prison, is testified, among many others, by Theophanes the Confessor, called the Branded. ...In one of the canons for the reposed he thus prays for them: 'Deliver, O Savior, Thy slaves who are in the [hades] of tears and sighing' (Octoechos, Saturday canon for the deposed, Tone 8, Canticle 6, Glory).
-- St. Mark of Ephesus, First Homily on the Refutation of the Latin Chapters Concerning Purgatorial Fire
I would have to say Yes it is "offensive to modern Catholic teaching and theologians/apologist", because ultimately he is saying "The Catholics are wrong, and here's why." If he were instead saying "The Catholics are right, and here's why" that would be another matter.
And if the points that he refused to accept dogmatically are not even accepted as such by your church today? Is there disagreement with what he affirms to be true? Is there a strict belief that the points he rejects have to be accepted?
It seems to me that the idea that Purgation, Hell and Heaven are "places" is part of the earliest and current understanding of the body and soul. The body and soul are not separable so that when the body dies, we seem to always posit some sort of material vehicle for the soul until it is once again reunited with our glorified body when Jesus comes again in glory.
The whole idea of immortal soul has its own problems, in terms of its apostolic origins, and I am very happy that was not discussed at Florence or we may have more of a mess than we do today. Nonetheless we cannot posit a body/soul dualism, nor are spirits immaterial, so it simply is reasonable to think of Heaven, Hell and Purgatory as 'places' with material bodies of some kind inhabiting them...whatever that means in life everlasting.
And fire, of course, is quite scriptural, old and new testament...It burns without consuming.
So I really don't get Bishop Mark's difficulty, and so I just ignore it and move on.