I agree with Kirsten. As already said in the other thread, you need to get him assessed asap and start training him and working through his problems with the help of a professional. It's good that you will be doing obedience classes with him, and if you can afford individual classes, or at least an assessment by a trainer who is experienced in training Service Dogs, then that will help too.
None of us here can tell you if he has what it takes to be a SD or not, but a professional who is experienced in training SDs will give you a better idea.