a separate 'army' should be created that does not focus on defence or military at all but on emergency service and relief for natural disasters and ecological and social assistance learning and using skills for building, repairing, planting, medical aid and even just plain old sandbagging. all can become trained volunteer fire fighters and assist in any and all emergency situations around the country and perhaps even overseas boosting out emergency services where ever needed. these skills are non violent and transferable when service is complete. similar to the peace corps but australian based. exemptions for those doing further study or with sole care of children.
Yes, if they are always in trouble with the law and police and they dont wish to remain at high school, Tafe, University or they have a part-time/full time job. They must have a thorough mental assessment. They then should be required to complete their education through the armed forces or social services.
Yes, in their own units separate from the volunteers. But not just Military give the people options to do "National service" such as in services such as the ADF, Paramedics, Fire Fighters or even community service with cleaning graffiti or picking up rubbish.