One thing I haven't seen in this discussion is any actual statement by Corbyn that could be read as anti-Semitic in general, rather than anti-Israel specifically. The only exception would be that mural, but that seems to have been a genuine mistake.
He really dislikes Israel and is willing to ally with actual anti-Semites who share the same dislike. That is a strike against him. Of the points I listed above:
The only ones that don't directly involve Israel are 1, 6, and 7. I'm willing to dismiss the Duke thing; it's true that real anti-Semites sometimes support whomever is anti-Israel (I've seen support for Palestinians on Stormfront, despite their usual hatred for Arabs). Number 7 is bad, but a lot of them involved extreme anti-Israel statements as well, that didn't touch on Jews in general.
I've never heard of him complaining about Jews in general, outside of Israel. No conspiracy theories he invokes involve a global Jewish conspiracy or anything of that nature. He's certainly never said anything negative about British Jews, and though Jewish newspapers in Britain have denounced him, they didn't present any good reason to think he would support doing anything that would negatively affect the Jewish community in the UK.
I also don't think it follows that moderate opposition to Israel's policies is not anti-Semitic, but strong opposition involving baseless speculation about Israeli covert ops is anti-Semitic. It is true that real anti-Semites promote wild conspiracy theories about both Israel and Jews in general, but what Corbyn said, while baseless, was about Israeli covert ops, which they are known to engage in throughout the region. It's plausible that they would try to intervene in order to help bring back a friendly Mubarak-like regime. Destabilizing the Sinai would obviously cause lots of problems for Israel too, so it's kind of unlikely they'd choose that route, and more to the point, he didn't actually have any evidence that they were actually doing this. So it's wrong, but not totally implausible, and not far-ranging the way real anti-Semitic conspiracy theories are.
Now if he said something about how Israelis are secretly manipulating much of the global economy through agents placed in large banks, that would actually be an anti-Semitic conspiracy theory. The difference, to my mind, is whether it plays into anti-Semitic tropes about global Jewry, especially involving manipulation of world economic or political events.
This topic in general is obviously a political play - most people who use this against him were strong opponents of Corbyn to begin with, and this is the most potent allegation they have to use against him. Obviously, as people said upthread, you could investigate the Tories and find plenty of racist and/or Islamophobic stuff said or tolerated by their members, probably considerably more than anything racist and/or anti-Semitic among Labour.
It's certainly a problem that he tolerates or even allies with anti-Semites when opposing Israel. But the evidence that he is personally an anti-Semite is weak and circumstantial.