becky, I don't think he will break anything if he comes into the home, but he very well may take some things that you won't notice are going right away.
I do agree that you should probably move all of his stuff to the garage and that way, you aren't looking at the stuff all of the time. If you can bag it up, use the black plastic luggage to do so (trash bags). Then if he says later he still has stuff there, ask for an itemized list of what he think he wants and have it ready.
I think you are very wise to have someone there while you are away from home.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.