Have you thought about doing a Finnair mixed class fare? Should be around $4k to do SYD-SIN in QF Y and then SIN-HEL-MUC in AY J. I think it's 3.5k to just do SIN-HEL in J and the rest in Y.

I have been to MUC a few times to snowboard Innsbruck. My favourite resort is the Stubai Glacier. It's a shame that no OW carrier flies into Innsbruck as the drive to and from MUC is a bit of a long one in bad weather or traffic.

Do BA still offer the free side trip to Europe when you purchase a WTP+ ticket?