As someone who has had hundreds of people stay in my home I believe I can answer that question. I think the most important thing is to screen your guests. Almost every exchange/home rental site allows you to screen guests/hosts through references. If you would feel more comfortable invite only people with several stellar references. I can honestly say that I have never had a bad guest. The “worst” things that have happened was someone broke a vase (they replaced it and didn’t know that mine was from Ikea) and someone burnt a hole in an outside chair cushion. Either of those could have happened with my own friends visiting! I have friends with a rental beach house and they have a closet where they lock up their favorite things, you could do the same.
I really don’t keep a lot of “valuables” – I believe in having more experiences than “stuff” but nonetheless no one has touched my furs or wrecked my house. I believe that most people are going to treat your house with respect. If you would feel safer, go ahead and get a rider on your homeowners – but my insurance company said because they aren’t long term renters, I don’t need a special policy.
One other thing I don’t see people do is create your own contract. All of these rental and exchange sites allow you to send emails/contact the other party – so make a great contract protecting yourself and your valuables and make them sign it. I am linking you to forms that you can adapt accordingly.
So the best ways to protect your home and valuables are: 1) check references 2) check with your homeowners insurance company 3) lock up your valuables and 4) write up a contract. Go Travel now!