Dear NEMO,
Your question concerning "Orthodox saints for Catholics" meaning those who were not against Rome et al. is one I've grappled with when I was first introduced to a deeper understanding of the Christian East by Father Serge Keleher when he was in Toronto.
I remember speaking to Fr. Keleher about the icon of the "Pillars of Orthodoxy" that includes St Gregory Palamas, St Photios, and St Mark of Ephesus.
Fr. Keleher responded by saying, "Yes, I have that icon . . ."
I asked him, "And . . .?"
"Well," he continued, "I wouldn't put it up in my church because some people would come by, look at it and say, 'Oh, dear . . .'"
Fr. Keleher continued by saying that the first two saints, Gregory Palamas and Photios the Great are "Catholic saints" and he referred to the book by Fr. F. Dvornik on Photios. We then discussed the history of the Council of Florence and St Mark of Ephesus which continues to be a lively topic for many!

And St Gregory Palamas has indeed been acknowledged by Rome as a saint (1973).
Historically, when individual "unions with Rome" were proclaimed by various parts of Orthodox Churches, the Saints on their calendars were "vetted" and those saints who were characterized by what was understood as a virulent "Anti-Papal" feeling were either expunged from the calendar or else left in the calendar as a simple commemoration without liturgical rubrics.
Also, what were considered "spurious" saints were likewise expunged e.g. when a group of Ethiopians came into union with Rome, the name of "Saint Pontius Pilate" was expunged from their calendar. I don't know if, today, this would happen, especially since the veneration of Pontius Pilate forms part of the historic tradition of Ethiopian Orthodoxy.
When the Union of Brest came into being, there were actually no saints that fell into either of the above two categories. It was only later that St Athanasius of Brest was glorified, and he had opposed the Union of Brest on the grounds that the secular government of the time (i.e. Poland) was using secular power to impose it (which was true).
After the first uprising by the Kozak Hetman, Bohdan Khmelnitsky in 1648, Athanasius, the Ihumen of Brest, was taken prisoner by the Poles, tortured for his attacks on the Union of Brest, and, as he refused to recant, was taken out, forced to dig his own grave, was then shot twice in the head, and was buried while still alive (this was known from the shape of his hands when he was later exhumed).
Athanasius was glorified an Orthodox saint and his cult immediately became an Orthodox rallying point against the Union of Brest. Pilgrimages were organized for his feastday on September 18th where "anti-Union" sermons were preached etc.
However, at the same time, many Ruthenian Catholics (i.e. Ukrainians - Carpathian and otherwise - and Belarusyans) ALSO honoured his memory for standing up to Poland - he became a national saint for the Ruthenians, whether Orthodox or Eastern Catholic.
To try and stave off his growing cult among Eastern Catholics (who, to the Jesuits' chagrin, were attending the pilgrimage to St Athanasius on September 18th), a new feastday for Blessed Josaphat Kuncevich was established on . . . September 16th, two days before St Athanasius' day.
Something similar occurred in Bohemia when it was found that Catholics there were beginning to honour John Hus (+1415) as a saint on July 6 and the cult of St John Nepomuk was organized, as Protestant historians especially maintain, to stop Hus' cult (also see Holweck, Dictionary of the Saints under "John Nepomuk"). As we know, in 1963, the Catholic Church took St John Nepomuk out of the universal calendar and left him in as a local commemoration.
It was Met. Andrew Sheptytsky who later restored St Josaphat's feastday to November . . .
So whether we see St Athanasius as "anti-Roman" depends on your perspective.
In the Baltics, there is the cult that is popular among both Orthodox and Eastern Catholics of St Isidore and 72 companions who were drowned at Dorpats in Estonia. The Latin authorities there ordered them to become, not Eastern Catholics, but LATIN Catholics. They refused and so were killed.
Even Fr. Holweck in his book on saints affirms they were martyred "for their rite and nationality" and thus takes them out of the "Catholic vs Orthodox" context.
And if we were to exclude from the veneration of Catholics seeking to look Eastwards all the Orthodox Saints who, at one time or another, said something against Rome or the Union of Brest, then the following popular Orthodox Saints would have to be shunned by Catholics:
St Paisius Velichkovsky, translator of the Philokalia (who likened the Union of Brest to "spider's webs")
St Dmitri of Rostov, author of the Lives of the Saints mentioned above, who was very "Latin" in his devotions and theological perspective, but who considered those who entered the Union of Brest as having "entered the ship of fools."
St Theophane the Recluse, teacher of the Jesus Prayer, whom one RC historian said "when it came to the Church of Rome, he repeated the prejudices of his environment."
And a number of others.
But they can certainly be forgiven as this did not characterize their lives and, in fact, they were fiercely loyal to the Orthodox Church.
The martyrs "against" union with Rome, I believe the case can be made, were reacting to something much more than simply union with Rome. In Athanasius' case, and that of St Isidore and his companions, to become "Catholic" meant not only to leave one's Church but also one's nationality - let's consider that for years in Eastern Europe one never mentioned one's actual nationality when asked one's cultural/national background. One simply said, "I'm Orthodox" and this meant that one was Ruthenian or if one said, "Catholic," then this meant one was Polish.
The Athonite martyrs who were burned on orders of the emperor for opposing union with Rome (i.e. the 26 Hosiomartyrs of Zographou Monastery), I also believe the case can be made, were opposing a politically expedient union that had no relation to theology (and in this, they would certainly be right).
Saint Mark of Ephesus actually came to the Council of Florence as a . . . unionist. He believed that the Filioque was a heresy - yes.
But he believed that God would heal the heresy once the Latin West was rejoined to Orthodoxy. He didn't, therefore, demand that the West retract the theology of the Filioque as a condition for unity, only that the Filioque be formally removed from the Nicene Creed.
He was against changing the ancient faith of the Church and philosophizing to try and "improve it" - and I believe that in this he was also most certainly correct.
I don't believe there is even ONE Orthodox Saint today who can be "expunged" by Catholics for reasons that have traditionally been given.
As for St Herman of Alaska, Roman Catholic representatives were present at his Orthodox canonization service, they reverently kissed his icon and relics, and were given blessed icons of him to take home with them.
If these RC reps did not acknowledge the sanctity of St Herman, then they should not have been present at the canonization, no?
And Russian Catholic parishes and some Ukrainian Catholic ones too (i.e. St Michael's in Welland, Ontario) do indeed commemorate St Herman of Alaska as a saint in their Litia service, for example, and have his icon.
Some Russian Catholic parishes also liturgically venerate the New Martyrs of Russia, INCLUDING the Holy Royal Martyrs of Russia.
But doesn't everyone?
I once received a letter from an Irish Catholic priest on the subject of the Pillars of Orthodoxy and he said, "We Catholics are entitled to venerate (Mark of Ephesus) privately."
Alex