I will on a business trip for a few days, so most of my posts will be from "rote," but I will do my best.
This does not imply that John VIII accepted as binding the theological statements of 879.
First, did Pope John VIII sing the proceedings of the Council or not? Second, Pope John VIII ordered the publication of the Creed of 381 (without the filioque) after the Council, in addition to accepting St. Photius' appointment. It doesn't get much clearer than that, P.
My understanding is that he did not sign the acts, that he merely sent a letter to the emperor praising the council based on the report of the legates, but when he finally received the acts sent by Photius and saw what the council actually said he then repudiated it. I would be interested to see what Dvornik has to say about this.
Second, Pope John VIII ordered the publication of the Creed of 381 (without the filioque) after the Council, in addition to accepting St. Photius' appointment.
Perhaps, but he did not condemn the filioque as heretical nor did he seek to suppress its teaching in the West, as opposed to merely insisting on keeping the formulation of the symbol of faith from Constantinople. As you say, it does not get clearer that that. I too would not be adverse to returning to the Creed without the filioque, but by this I would not hold that the Western formulation was heretical.
BTW, Dvornik's book is "The Photian Schism: History and Legend" (1948). I was going to by a copy but Amazon lists it as $298! I will see if I can locate a copy in a library.
For what it is worth, I found the following at angelqueen.org:
Well, Dvornik gives the sources. The decisions of the Photian council - in which every addition to the Credo was condemned - were brought to Rome by the legates. John, as a matter of fact, didn't excommunicate Photius. But he also didn't approve of the synod as such. In his letter to Photius, he writes: ""We also approve what has been mercifully done in Constantinople by the synodal decree of your reinstatement..." And in those to the Emporor Basil, he writes again: ""We also approve what has been mercifully done in Constantinople by the synodal decree of the very reverend Patriarch Photius' reinstatement..."I cannot vouch for the accuracy of this report until I have a chance to consult Dvornik myself. Take it, therefore, cum grano salis.John hasn't approved of the whole of the synod, but just the decree that reinstated Photius. He also hasn#t anulled the anti-Photian synod(counted by Roman Catholics as Eight Generel Council), but has abrogated the disciplinary measures that were taken in this council against Photius - or, to say it better, he has, in his own words, "mercifully" dsipensed Photius of this penalties and approved of him as Patriarch. But, in fact, he has only approved of this very decree of the Photian synod, because he goes own in the letters both to Photius and Basil: ""If perchance at the same synod our legates have acted against apostolic instructions, neither do we approve their action nor do we attribute any value to it. " Of course, he hasn't conferred to his legates the mission of conmdamning any addition to the Creed!
Above, I quoted that John has condemnded the Eight General Council. However, Dvornik shows that Photius and the legates changed the original words of the Popes letter to the Phoitan Synod. It's probable, or even sure, that John only abrogated the Eight Council insofar as it was set out to condamn Photius - but the other canons remained intact.