Teaching broad religious awareness and tolerance in government schools won't work for the simple reason that we can't make atheism a condition for hiring teachers. How can we expect religionists to present their faith as just one of many equally (in)valid belief systems?
In my government school we had a core subject innocuously called "Life Options", taught by the school's chaplain. We spent countless hours poring over the class copies of the New Testament, but I can recall only once looking at a non-Christian text - a single page with some particularly gruesome text from Zoroastrianism. The message? Christianity is the only religion that teaches love.
I don't doubt the good intentions of the school or the chaplain, but even with class copies of the Talmud, Holy Koran, Book of the Dead and Vedic scriptures, there are no guarantees that religionist teachers would give equal time, weight or credit to the different faiths. The risk of privileging one faith over other views would so undermine the laudable goals that it is better to just leave it out of the curriculum entirely.