You could just put all of your rules (and monetary consequences) in the Rules of the Road section on your listing. The rules get printed on the renter's booking receipt and you can print it out and have them sign it at the beginning of the trip. This way they see your rules on your listing and then you can go over them as part of your walk-through and they sign it agreeing to your rules for how you want them to take care of your rig. Outdoorsy is also having a webinar about the Rules of the road this afternoon at 5pm central time. I'm sure you could ask about SRAs.