Taken individually, the new Off Broadway shows “Hannah Senesh,” “Jewish Plot” and “Playing Shylock” are frustrating, sometimes perplexingly so, pieces of theater. But taken together they offer a composite look at concerns over Jewish identity and issues of stereotyping and art. The most straightforward production is David Schechter’s “Hannah Senesh,” which is presented in English by National Yiddish Theater Folksbiene (at Theater Row through Nov. 9). This hagiographic solo show retraces the real-life story of a young Jewish poet and resistance fighter who was executed during World War II — Jennifer Apple portrays the title character from the age of...