Everything @Knowsstuff is exactly what I would say in answer to this. Being a big feeder school to UM means they know your school and know the rigor, what the classes are like, what an A really is there, and even what the teachers are like. Good AP scores will affirm that.
Have a great first semester because it looks as though Michigan has decided to stay with the late January notification period, which means if you have 7th semester grades send them, or even 1st quarter. Based on this past admission cycle, anything you can do to add to your application to strengthen it you should do. This cycle was a beast and I think next year will be just as difficult, especially if it is true that they over-enrolled.
Michigan is one of those schools that really wants a score. Even a PSAT if not an SAT or ACT. So work on getting that up. That seems to be your only weakness. Everything else looks fantastic but we’re not AO’s so never now what they really want. Write an essay out of the ballpark because at the end of the day that is probably what really sets candidates apart.