Britney leaving the Chateau Marmont, Jan. 30, 2007, top, and shopping in Beverly Hills, March 16, 2005, bottom. X17online.com (left), Ramey Photo (right) Britney Spears has traded in the crucifixes and red strings for the Star of David. Is the Hebrew symbol in homage to her new man, a Jewish model-actor named Isaac Cohen? Spears, …