It´s much simpler for me:
Any good route westbound (!) from Germany with not too much stops (figure around 5-6 w/o transfers) covering Brazil, Hawaii, New Zealand and maybe South Africa flown in Business Class on *A.
Alternative would be to go from Hawaii directly to Japan, Korea and then head home.
All those usual spots like BKK
and the U.S. I would skip out as RTW-stops as they are too easy to reach for me (and reachable at reasonable prices).
Carpe diem ! Life is too short to waste your time ! Keep in mind, that today is the first day of the rest of your life !