You need to clarify your routing on OW flights. You can't use AS on an LONE4 even with a QF codeshare number. If you want to use AA for LAX-PDX-ABQ that will require 4of your 6 flights in N AM. There are are no single number flights for DEN-BOS, BOS-ATL so that will require connections. I would save a segment and take the bus between KUL-SIN or buy a LCC return. Try this.
CBR-SYD-LAX//DFW-DEN-ORD-BOS-DFW-ATL-LHR-SIN-NRT-KIX-SIN-MEL-CBR