Nope. You cannot connect in any third region when traveling on a North America <-> South Pacific "oneworld and other airline" award using AA miles.

Combining a North America -> Asia 1 award in F with an Asia 1 -> South Pacific award in F would cost 122.5K AA miles. The latter award would allow a connection in region Asia 2 (which includes SIN). Note that based on your proposed itinerary, stopovers would be allowed only at DFW and NRT before you reached NAN.

Also, the region connection rules are not the only rules to consider. There's also the published through fare requirement, which might be especially problematic for a
NRT -> SIN (JL) -> SYD (QF) -> NAN (FJ) routing.