Yes, El Al did have this rule where they did not fly on the sabbath day, but if I am not mistaken, I think a few years ago they abolished that rule. Maybe some one else knows more on this.
On the contrary, there is a lot of traffic to Thailand. Heaps of Israeli tourists go there. El Al also carries a lot of Israeli tourists to India(Mumbai and Delhi). Singapore is a market that has been untouched , perhaps there are no Israel-Singapore diplomatic relations. As for Indonesia and Malaysia, out of the case being moslem countries. The route to Australia will do well because the Israeli tourist market to Australia is virtually untapped.
I know El Al fly to Hong Kong twice a week, so they could code-share with QF either via HKG or BKK.
Who knows, with their new order for 330s and 777s and the possibility of flying here non-stop, something might work out.