how long do you suggest roasting the vegetables for? Also, can this be made a few hours in advance and heated again prior to serving?

Brussels sprouts and butternut squash will need about 20 minutes. The apples will be done sooner and you may want to remove them when they are done.
Generally speaking you can re-heat stuffing. I would re-heat covered for sometime until warm and then finish the heating up uncovered to re-crisp the topping.