These things could happen, but since the product/service is about carpooling, I tend to pick up the same people repeatedly. Any time you work with a new person, there is a risk. That risk goes down significantly with repeated rides. I initially had issues with pick up and drop off location, due to Waze letting you pick how many minutes you're willing to walk. With new riders, I have a chat before accepting so they understand the nuances of Waze Carpool.