score:3
This might work:
Train Freiburg to Zurich airport, 18:12-20:21
Fly Zurich to Singapore, 22:45-18:00 (Sat)
Fly Singapore to Sydney, 20:05-06:50 (Sun)
Fly Sydney to Adelaide, 10:25-12:00
Or you could go directly from Singapore to Adelaide and save yourself 3 hours.
Upvote:2
OR
THEN
The check-in/bag drop deadline at Basel is 19:50.
This one is probably not doable if you have hold luggage, as the check-in/bag drop deadline is at 21:15.
The best option is still probably the one via Zurich.