Moree is a bit out of the way unless you want to take all your freight via
Dubbo to Sydney. And then you still have to get it down the Blue Mountains.
Even if you followed the existing line from Moree to Sydney you still have
to get over the Wellington Range between Werris Creek and Scone.
Sydney - Tamworth - Tenterfield - Warwick - Brisbane has been suggested as
an alternative to the north coast line. The existing line (with deviations
as required) could be used to Tenterfield, then a new line built to
Brisbane. Transit times would probably be about 15-16 hours. The crew
change point would probably be Werris Creek.
As to passenger services, the Xplorer currently does Sydney to Armidale in
7 hours, 45 mins. With deviations this would probably be reduced to about
7 hours. An XPT could easily run Sydney to Brisbane via Armidale under
12 hours.
Cheers
David