Don't know if your ex is like mine, but I had to include no alcohol, no smoking in enclosed spaces with the children. If he is taking them to a party/BBQ he must have a designated driver.
No beach vacations with the little one until she learned how to swim. Even then, she has to have a life jacket at ALL times. He likes to play sports on the beach and drink beer and he will *no* be standing within arms reach of a 4 YO the entire day. Thank god I was able to refuse to send her along until she got older.