We always tell people to go with their gut first. If you don't feel comfortable with a home exchange proposal, a polite no thank you saves lots of hassle latter on.

You can also ask for references from previous home exchange partners too.

We really liken home exchange to Internet dating. By the time you are ready to meet for coffee, you have already exchange emails, phone calls and photos. Same with a Home Exchange. You never trade with a stranger, but the process of selecting and then arranging an exchange leads to emails, trading photos, phone calls, etc. so in the end you are never trading with a stranger but with someone you hand selected from the site, liked enough to email, there was a connection there and you guys hit it off enough to trade homes.

It's like a natural selection process, and the detail that is provided in the actual listings goes a long way to allowing the right kinds of people to find each other!