Until you get the large speakers hooked up as fronts, the 'all channel stereo' (stereo front-rear on my system) is the only way to get full-content signals to them. Otherwise, they receive the rear-channel signals.

How about just swapping the 'front' and 'rear' speaker wires at the receiver for now. At least you'd have the best signals going to the best speakers for the job.

As far as mountains in Australia, I found a link about the Blue Mountains among others in a search for "Australia mountains". So, I'd have to say "yes", but I don't know about skiing. Ask Aussie.

Larry
www.fineeleectricco.com