Cohen as a first name? No different to Levi, which has been used by non-Jews for centuries. I have no issue with it.
Criticism of Israel is legitimate, but has the potential to be anti-Semitic. What deeply frustrates me is when people make snap judgements based on one-sided stories. And I don't mean the Israeli 'side' or the Palestinian 'side'. When people get all their info from one source it can never be truly balanced. It is a sad, angry situation and hugely more nuanced than most people realise.
Jesus Christ? Most Jews accept he existed as a man, but all deny any divinity on his part. We do not believe that he was the Messiah. We have no argument with many of his statements, such as love thy neighbour and the glass houses one, but utterly reject the concept that you can only approach god through him, or that he could take the burden of anyone else's sin.
Some of my ultra-Orthodox relatives would not even discuss him or mention him. This, I think, was a hangover from centuries of Christians encouraged to commit violence against Jews in Jesus's name. It is difficult to conceive of an era when this was acceptable, but it was, in my parents' lifetimes.
Personally, I think he was an ordinary but charismatic Jew, influenced by the Essene cult, with a message of peace and focusing on the meaning of Torah over rituals, that was distorted by the followers who came after his death.