CrazyJ82: I think you have to ignore the two legs between LAX and LAS to get the correct result because including these legs will exceed the li it of two transits.


OP: Your plan and calculation is correct. As mentioned you will not be able to upgrade for las -lax and i dont think AA offers J in this segment as well (its just a short flight anyway). CX can do a partial upgrade as well.
Btw, I think it will be a waste of SPG points in converting to AM.