Sorry I am new to this type of tix

If I am flying LAX/ORD/DUB and simply connecting in ORD, Can I take the non stop mileage calculation of 5140 miles or do I have to take the 5400 mile calculation.

Also if I were to start a Global explorer fare in Lima , Peru, do I actually have to return to Lima or can I finish in another SA city?

Anyone know if the fares listed on OW web site, include any taxes etc?

tks