You get a warning several real days before auto-bankruptcy. "You have x days until bankruptcy" or something like that, and it is repeated daily so you know whether you are still in danger. I have gotten the warnings in my email as well as ingame, but that might depend on you settings.
The load factors are calculated based on a number of variables including the ticket price, seating comfort, schedules, frequencies, company and route images of yourself and the competition. There is also some slight random fluctuation, I believe.