https://www.washingtonpost.com/news/acts-of-faith/wp/2016/11...
As for who wrote the executive orders:
" Inside the West Wing, it is almost impossible for some aides to know what is in the executive orders, staffers say. They have been written by Stephen Miller, Trump’s senior White House adviser for policy, and Steve Bannon, Trump’s chief strategist, according to people familiar with the matter. Ideas for some of the Trump executive orders came from transition officials and so-called “landing teams,” " --http://www.politico.com/story/2017/01/trumps-flashy-executiv...
How can someone be pro-Israel and antisemitic?
https://theintercept.com/2016/11/16/steve-bannon-made-breitb...
http://forward.com/news/israel/354402/how-steve-bannon-and-b...
And of course he would put up working with Jews if it meant he had a seat at the table and a chance to enact his wildest dreams. In a choice between power and principles, most people chose power. Your proposed Occam's Razor doesn't work because you're ignoring the most obvious thing: the desire of people for power. If being Trump's right hand man means putting up with Kushner, then so be it. I'm sure Kushner, as the other key figure standing beside the throne, feels the same way. He can put up with an antisemite in order to be in the White House.
Think about it. Occam's Razor is for the simplest choice. Assuming Bannon's racism, Bannon's choice here is: work with Jews and have a lot of power, or avoid Jews and go back to the mundane life as a publisher with no seat at the table. There's really no question of what he would choose.