Abandoned Property

My son left the service (Coast Guard) where he was stationed in Florida and returned home to Michigan 3 weeks ago. He left behind a considerable amount of property in a friend's home (where he was living). The friend is involved in a bitter divorce situation and has moved from the home; ex wife moved back into the home and is now refusing to allow my son to return to claim his property. Is there any recourse that won't cost $1000 or more in attorney fees? She has said she will get a restraining order if my son shows up for his property.

I have a renter keeping his aircraft in my hangar. He has not paid rent in almost 3 years. We have a written agreement which says he owes me $100/month. I would like to give him notice that I will start selling parts of his aircraft to cover the almost $3,000 that He owes me. He refuses to answer any of my requests and lives out of state. How can I recover this over due rent?

A live-in employee quit and left her belongings for us to store. We have asked her multiple times to pick up her stuff and currently are paying to store it. How long do we have to wait, and what steps can we take to get rid of her stuff?

Exactly what steps do I take to claim the balance of the sale of the contents of self serve storage facility which was sold at an auction?

A customer has left a piano at our place of business for more than five years. She has refused to pay rental or moving costs and other repairs we did. She has moved and will not give me her current address, though I have her phone number. I have sent papers advising her of small claims court procedings, but she will only give me a PO box number. How can I precede with small claims court? What is my best course of action?