1. Overworked? I would say no, compared to other airlines. My medical normally sees me writing between 450-500 hours for the year on the form. They will try and ensure they write the schedules such that we will have one day off in seven but that roster will most likely have standby days where you're not called and occasionally groundschool, emergency training, sims etc. With normal days off, commuting days and vacation days they only have you for 197 days per year.
2. Tiredness is certainly sometimes a factor but show me a 24 hour airline where it's not. It's not nice flying from RGN to NRT through the night but you're never going to see daytime only flying in an organisation such at AJX, so you have to suck it up or go and get an office job somewhere. I don't think fatigue is an issue at the moment. It has been in the past and at one stage the scheduling was really going downhill as far as fatigue mitigation was concerned. However, for the most part, I believe they've listened to what has been said and now try to schedule more sensibly. In my opinion fatigue is brought about by cumulative knackering trips, not an individual trip interspersed with others. Maybe I've been lucky but I really don't see others doing multiple knackering trips in a row and being genuinely fatigued. Tired, sometimes, yes but (at the moment) I don't see fatigue as a major factor.
3. Probably half the roster is night flying. There are some passenger day trips and maybe one or two cargo day trips but most of the flying will be either day into night, vice versa or a day flight to somewhere (e.g. RGN) and a night flight back. If you're scared of the dark then don't apply.......to almost any airline.
4. Again, I believe they have listened to what they've been told about the day/night switching and tried to reduce it. I don't mean during a trip (as I've mentioned above) but if a trip is, for instance, a night cargo flight and your next trip is a day passenger return flight then they'll generally split it with a standby duty or a day off (blank day) if you're close to requiring one. Going from day to night is not normally the problem as you have the time before the night flight to try and rest but the other way round reduces the options and that's why they'll try to stick something in between.