1:25 may be tight, no? But QF F > KE F IMO.
But is QF F + EK F > SQ R + KE F?
So I can fix the connection problem, exchange KE F for EK F with the following itin.

SYD-SIN = SQ R
4:05 connectionSIN-DXB = EK F
3:40 connection DXB-JFK = EK F
Departs SYD Weds. 3pm - Arrives ORD Thurs. night