To answer your initial question, your relative (the one with the mileage -
) can request a ticket in your name. You should warn them that they'll probably spend quite a bit of time (hours) on the phone with their FF program to set everything up.
Originally Posted by
mobilebucky
*A 16 segments & 39000 miles RTW limitation only applies to purchased fare. If it is using miles it depends on the FF program, some only allows 5 stopovers total.
Specifically, for UA, the max numbers are 16 segments, 5 stopovers, and 36,000 miles. At least that was the situation a year ago when I booked a similar trip for a relative.
As was noted previously, your trip is too ambitious, you are way over any likely stopover limit your FF plan has.