According to FAQ, religion questions are off topic, see: Are religious questions on-topic?
So why aren't all the questions about Catholic Church being closed? Why is there even a tag catholic-church? I though this was supposed to be site about scientific skepticism.
EDIT: An example: Has the Catholic Church ever retracted an "ex cathedra" statement?
Well, they aren't closed because they collected hardly any close votes. So there does not seem to be a consensus at this moment that those questions are off-topic.
I also would not regard those questions tagged catholic-church as being about religion, they are about the institution, not about the belief. And the catholic church has certainly performed actions in the worldly realm and it has also stated claims about worldly matters.
The questions are about claims or actions by the catholic church, I consider those things fair game for our site. Only questions about religious belief are off-topic. If these questions at some point devolve into religion bashing we would need to step in, but otherwise I see no need to intervene.
According to FAQ, religion questions are off topic, see: Are religious questions on-topic
The answers in the FAQ explicitly state that questions about faith are off-topic. Questions about religion may be questions about facts, though, and therefore fall into the realm of scientific skepticism. For instance, the claim that “visitors of Lourdes experience spontaneous recovery more often than would be expected by chance,” while a claim about religion, is still a claim about facts, and it has an answer (there are publicly available statistics about that, and the claim is of course false).
Likewise for the question you referred to: in its revised form, it has a clear, unambiguous answer. This is applied scientific skepticism.
That question is open because the community decided to reopen it, after Suma and I closed it as off-topic.
Once the question got reworded and 4 reopen votes I've tried to salvage the situation by making it more historical. Normally moderators will not override the community in such matters.
But, I agree, it's a really bad question and if I had a normal close vote it would be there. It's not about religion anymore though. It's about religious matters (i.e. the church), but not about religion itself.
I'm not even sure why this is being asked; Fabian's answer in the question you linked to HERE seems to cover exactly why questions related to religion or with the tag catholic-church or about religion in general aren't closed in a de facto manner.
I asked the question you linked to as an example and agree that it was not worded well to begin with. The close votes and comments by Slivvz significantly helped refine things. It seems like this is why reopen votes exist in the first place.
I have an objection to others not linking the subject matter (religion) and automatically assuming it's unanswerable. If one looks at the revisions and some comments, I tried to give examples of exactly how this question could be answered. For example:
The Church hans't done that, but it's not the point! The point is that such proclamations, intended to be infallible, could intersect with testability. This still wasn't met with an open mind, in my opinion.
Lastly, to re-answer your question...
Off-topic/closable: Untestable, intangible, meaningless questions. Basically, if it's not even possible to find data or conduct an experiment to answer the question, it violates the rules. Examples:
On-topic/acceptable: Questions in which religion or a religious institution intersects with an area that is studied or for which there is data. If you look at the questions that come up with searching the word "catholic" (LINK), you'll find that these are mostly about sociology, history, or simple queries that might or might not have data (Is the Bible the most read book).
Again, I consider this to be a regurgitation of Fabian's answer that already exists; this question seems redundant. Re-read Fabian's answer and you'll know exactly why so many questions about religion are open, getting answers, and getting upvotes.
The question presented as an example is way off-topic, and there have been varying explanations and justifications for what's being asked.
While the question currently asks whether the Church ever retracted a statement made ex cathedra, there's a bunch of speculation about what constitutes a statement made ex cathedra and if the Church is justified in making statements ex cathedra under certain conditions.
Additionally, Hendy's answer here points to a completely different question: whether statements made ex cathedra (or even papal infallibility, a whole other topic) are falsifiable in principle.
So we have a bunch of questions:
This list alone should point to the question being an excellent candidate for closure as not a real question: it's not clear what is actually being asked other than something related to papal infallibility.
But taking each question by itself, all but the first are off-topic here: Skeptics.SE is not in the business of questioning doctrines of faith. They'd all likely be great questions for the up-and-coming Christianity.SE, but they are bad questions for here.
So it just leaves one question, which is what the question title has been edited to be (nevermind that's not the question body asks, or what people answered). This question is wholly uninteresting: it's a yes or no question that's easily available to anyone who looks (spoiler alert: the answer is no). It's not a question of scientific (or any other kind of) skepticism: there is only one authority who is capable of retracting a statement, and you just need to ask.
Think of it this way: let's say I make the statement "Puppies are ugly." You can ask me, "do you retract that statement?" If I say "no," that's it. There's no deeper mystery here, and there's no need for skepticism: I just provided you the answer to the question, "Did Mark Trapp ever retract any statements about puppies being ugly?"
Being a religious institution does not add more mystery to such a question, which is why I can appreciate how the question turned into this amorphous blob of several other interesting (but wildly off-topic) questions. But being uninteresting isn't a justification for keeping a question open or for it to go off the rails like it has.
To the other questions in the catholic-church tag, they all seem to be valid and on-topic questions for Skeptics.SE, although tagging them all as such seems to be misguided:
These questions aren't about the Catholic Church: they're claims made by the Church. In some cases, the claims questioned aren't even exclusively held by the Church. It seems as pointless to tag them catholic-church as tagging a question "Is the sky blue?" with mark-trapp because I told you it was green.
In this particular case I think that editing the question was a mistake. The question as asked before was complete off topic, and the edit has changed is substantially to the extent it is now a completely different question (e.g. the answer already present makes no sense any more with the new wording). I think it should have stayed closed and a new question should have been asked instead, if necessary.
