We're working on getting a system in place to manage the tolls.
Our renters are vetted with an extensive Driving Record Check, so they're highly unlikely to get a red light/speeding ticket, though it's possible.
Visible damage is covered by our insurance policy as well as liability, and we now take pictures of the cars' interiors and exteriors to keep track of this. Invisible damage is covered by our mechanical damage policy, which owners can make claims from when they notice something happened to their vehicles.