I would consider myself an expert on this topic
I believe that the reason that many Italians and many Jews are genetically similar is that both groups are made up of a mixture of middleastern/Mediterranean and northern European DNA. Many if not most of the Jews of Europe descended from the middle eastern peoples (ancient Israelites) and got mixed with German and or European blood.
Now many Italians have the same type of background. Remember, for example that the Etruscans and the Phoenicians (middle eastern peoples) both colonized Italy and got mixed with the people of the Italian Peninsula who were already there (Sabin es, Brut ti,) and later Germanic and other northern Europeans invaded Italy and they were mixed in.
So to conclude, both Italians and Jews are a mixture of middle eastern elements and northern European elements (for the most part or a large part).
Now as for the catholic bashing. I have my reservations about this pope, however the catholic religion that I grew up with, had nothing but respect for Jews. We even visited a synagogue when I was in catholic school and we were taught to respect the roots of our religion...the Jewish faith,
It all comes down to this...I DEFY ANYONE TO RECITE a quote from Jesus where he said to harm or be disrespectful to Jews. A true catholic follows Jesus not the pope when he's obviously wrong or goes against Jesus' teachings.