Would it be possible to book a *A award with the first leg in ANA F from JFK-TYO then TYO-SIN-CHC in SQ F/J?
There is no such SQ/*A routing as JFK-NRT-SIN-CHC. Since you are essentially trying to book JFK-CHC, you'll have to make 2 separate award bookings if you want to stop in both NRT/HND and SIN on the way.