I want to know if there are any stats on family breakdowns and infidelity and are any airlines addressing this? My wife and children are more important to me than anything
If the last is true, you don't have to worry about the first, because you will quit the job at the first sign of any strain...
The REAL question is whether your being away will strain your relationship enough to cause it trouble. Is your wife an independent sort, who will thrive (not just "survive") in your absence? Will your kids understand your absence and thrive with just their mother around half the time? Will you make up for your absence when you return?
In my case, I suspect that being away from my wife half the time for the past 27 years has helped keep us together!