Hey Matt welcome mate. It is almost time for your tridy to go nina nana.(dorment) Not sure when that will happen for you up there but am sure that someone from up there will chime in. You should join a local bonsai club in yout district asap. They will always be able to help with specific local info.
Back to your tree; You can cut dying leaves off no prob. I would reccomend that you have some seasol handy and also some yates liquid tomatoe fert. Between now and when it drops its leaves alternate weekly, 1/4 strength mixes. this will put your tree in good stead for its dormancy, work to come and awakening in Spring again. As soon as it drops those leaves, then is the time to do any pruning, chopping and wiring. Repotting will need to be done as soon as you see buds swelling. My guess is that up there your dormancy has a smaller window of oppertunity and hence why i say to get in with the locals. If you are a keen gardner then this stuff is just logical common sense.
When the tree is naked you should put up a pic or two here for some styling advice perhaps. Stay cool, enjoy and stay in touch.
