I am so glad for you that your son will be home. But I think you should clarify the Lorezapam (aka Ativan) issue before he does come home as he may need it for behavior control. It seems like it's been helping him in the hospital. Another med that is in the same class as Lorezapam is Clonazapam (Klonopin) and this one seems to be used more to help kids with the behavior and anxiety issues. Ativan is probably not good for kids for longer term but Clonazapam may be a better choice, from all that I have seen and heard and from my son's own experience.
I would at least ask your Dr. to have it at home to use as needed. Let us know how he does with the homecoming and I hope it is a good one.