Plausible cases against the Pope, except I have no reason to build a plausible case against him: he defends the apostolic faith.
Hrm. Then perhaps you should focus on building a good defense. The reason I converted to Orthodoxy myself is that there were no plausible cases for
supreme papal jurisdiction. Protestants are looking at such cases to make the deciding factor for their conversions far more than any anti-Westernism/papalism/etc (such things can be legitimately picked up after conversion without them being a deciding factor for the conversion).
As well, at the time of my conversion the then ruling Pope certainly seemed to defend the Apostolic faith, I didn't see how the same claims could be made for the entirety of the 2000 years of history for the Roman See. It certainly seems that quite a bit of sophistry is needed to explain some of the stickier points of the history of the papacy- far more than is needed to confront Orthodox ecclesiological puzzlers.
You could build a logical argument, based on a premise of faith, that the planet Uranus is made of green cheese.
Indeed. Though it seems to me that cases for and against the papacy are more related to logical arguments, based on premises of faith, as to what makes a planet. So long, Pluto.
In every age since Christ, among all men in all conditions and all cultures, the Catholic Church simply is.
I think this is one statement with which everyone on the board can agree. Too bad that isn't the argument. The argument is which church can legitimately claim to be the Catholic Church. Even accepting the claims you've made elsewhere that Orthodoxy is simply a political division caused by the Turks after the fall of Constantinople, we have the multiple strikes against the Roman Church within the very same century. If the Pope is supposed to be the font of unity, he certainly seems to have done a very bad job of it.
This is not to say that Orthodoxy doesn't have some historical strikes against it as well. We have to come up with conclusive arguments as to how councils work when we have the Oriental Orthodox Churches running around (though that could easily be a strike against papalism as the source of unity, as well. Nice job breaking it, Pope St Leo. I kid.). But, as you've pointed out, logical cases can be built off of faulty foundations. There is no absolute surety either way, save the return of Christ Himself to sort this all out (at which point, I suspect, we'll both be in a little trouble- He'll probably say something along the lines of "I'm pretty sure I sorted this whole thing out when Sts James and John tried to take control seating arrangements in the Kingdom").
The more times I see this argument go 'round, the more I'm convinced: a) I'm completely comfortable where I am and don't doubt for a second that I made the right decision; b) even if I did, VII says that I'm perfectly fine where I am, no need to bother moving; and c) which is all for the better, anyway, because if I did move, all I would be gaining would be the pope and a host of bad liturgies (not anti-Westernism. I actually appreciate a good Western liturgy. Too bad they don't exist in America anymore).