Yes. ARDS can be caused by many factors, usually overwhelming sepsis or infection. If that scenario happens again, ARDS may return. Having it once does not make someone immune to suffering from it again.
Yes, independently. ARDS is the body's overrraction to infection or trauma. Younger people often are more susceptible. I have not heard of people being predisposed genetically, but there is nothing to prevent it from happening again if the same risk factors and events occur. It is not yet fully understood and research is being done to improve treatment and prevention.