Passports are the gold standard in ID. You need nothing else.
You should never pack anything valuable in checked luggage. So keep your camera in your carry-on. X-rays are a form of light. If film is exposed to light it is ruined. Digital cameras have no film, so there's nothing to be damaged by x-rays. Digital camera memory cards are exactly like CDs and computer hard drives, which pass through x-ray machines all the time.