You made a business decision, if you felt uncomfortable with it then don't do it. If the revenue and good will is not worth the effort then I agree, otherwise think of ways that would have made your more comfortable for you and your guest....
For instance, if the person sent you a copy of their drivers license and you had their cell phone, that may help. If you met them at public place like a coffee shop or gas station near by first then took them to the location so you didn't have to give the address, would that work since you could have said "sorry I don't think this works" and then just left?
I try to look at problems as opportunities, had it all worked out and you appeared to have bent over backwards for your guest, you may end up with a repeat customer. This whole business (and it is a business not a hobby) is about hospitality.