A valuable feature to add would be the ability to verify and/or capture a guest’s identification. The only site that I’m aware of that verifies identification is Airbnb.
Something that people may not be aware of is that if a guest uses a stolen credit card for the purchase and damage deposit, both charges will be reversed by the bank and the host left with a large liability.
There are some some providers that offer this function, but so far I haven’t found anything that’s compatible with Ownerez. So it would be helpful if you can build it into your offering. Perhaps an upload button on the rental agreement form so guests can upload their ID with the rental agreement.