When people view your home without a realtor, they are normally absolutely fine with you being there. In fact, they almost expect it - they don't expect to get to walk around your home unsupervised. It's also a great opportunity for them to ask questions and for you to give them some of the key selling points of your home.
If you want, you can also choose to have buyers (who aren't working with realtors) ID-verified before their showing. If you choose that option, we ask people to submit a copy of their passport/drivers license before they're allowed book a showing (like you do on AirBnB before you can make a reservation).
In the very unlikely event that anything does go wrong, or get stolen, it would be covered under your home insurance. This is also the case when you're working with a traditional realtor.