No, Israel is definitely the world leader in spying. They have a wonderful relationship with the American political class, enabling access to what the US has, and with asymmetry protecting Israelis over Americans, plus their own clandestine spying against influential Americans, and their operations all over the world. Their part among the players doesn't detract from grievances against Israel - it adds to it.
In terms of number of people spied on to number of people involved in spying, sure. China and U.S. are probably the world leaders in spying; its just a smaller percentage of the economies of both
There are dozens of firms in NATO countries and especially the US that do this kind of signals intelligence and surveillance work. I see no evidence at all that the US IC uses Israel for any kind of cover; we have native firms enabling sigint at the highest levels. "Cover" only makes sense if you're using it exclusively, but most CNE enablement work in NATO is done by NATO firms.