This meta-question throws around a lot of sub-questions (which explains why different mods have tackled different parts in the answers.)
Is the supernatural a taboo subject for skepticism?
Taboo, in the sense that we are embarrassed to discuss it in polite company? No.
Taboo, in that some aspects of it are off-topic for the site: Yes, but only some aspects.
The Help Center explains that we are about applying scientific skepticism. Science is about explaining the natural world. So, if an answer relies on supernatural claims, it is outside of science, outside of scientific skepticism, and off-topic for the site. No supernatural in the answers please.
In the questions, we do tackle supernatural claims - and look for natural explanations. (This leads to skeptics being attacked by supernaturalists for being close-minded, in that we don't look for supernatural explanations; nothing is "really supernatural". In the defence of science, when there is good evidence for a phenomena outside its definition of natural, it attempts to extend its theories to include it.)
In such cases, we stumble a little when asked broad questions, like Do ghosts exist?, but excel when asked specific questions like Is this a ghost?. Both of these questions demonstrate, the supernatural is not a taboo topic here.
From my reading of the scripture it appears as if the man had the supernatural influence, not the bone. All you have to do is assume the bone is as strong as any other bone and see what you come up with.
I don't believe that is a fair reading, or a fair assumption, which brings us into a nest of problems about where this question is leading.
The original question read to me as an attempt to prove that this biblical passage was untrue. If that was the intent, it was misguided. Both the believers and the disbelievers agree that such a feat is beyond what is naturally possible. (Where they differ, is some say this is evidence that God was involved, and others say this is evidence it never happened.) Showing it is not naturally possible does not disrupt the original claim; hence my point that it is a strawman.
From here, there are a number of directions to take it further:
"Settle an argument between OddThinking and me: When the spirit of the Lord infested Samson, could it have affected the strength of the jawbone?" - Off-topic on Skeptics, because no natural answer can address it. Probably on-topic: Christianity.SE, Judaism.SE, Hermeneutics.SE, Scifi.SE.
"Suppose the jawbone is supernaturally affected. How strong is it?" Off-topic on Skeptics, because no natural answer can address it. Unlikely to be on-topic in Christianity.SE/Judaism.SE except perhaps to address the theological question of whether it is infinitely strong.
"Suppose the jawbone is not supernaturally affected. How strong is it?" Off-topic in Skeptics (not notable). Maybe Physics, but I think they would prefer to talk about the stuff that is published in journals.
"Does the Bible originally say Samson killed 1000 people with a single jaw-bone?" - Probably On-Topic on Skeptics. Hermeneutics.SE would be a much better community to give an answer.
"Historically, did Samson kill 1000 people with a jawbone?" On-topic on Skeptics, but History.SE would be a better community to give an answer.