I don't work at THY but from my experiences and what I've heard:
- If there is a very big need for upgrades and they cannot find turkish people to upgrade, you might be upgraded but if you only have a high school diploma it will probably not be coming unless things change. Do not go there for a nice long comfy career, go there to collect money, enjoy a different culture, make some hours without expecting too much. Turkey is very different from Europe.
- About the rosters I don't know anymore but you work alot and expect alot of changes with a short notice. There are alot of nightstops and some days are very long.
- Alot of night stops, some places are really nice like in central Europe but also mogadishu, Uganda, Rwanda, Iraq, Afghanistan, Nigeria etc. THY crew is very arrogant but as a pilot you will be respected by everyone except the captain. You will understand what i mean during the line training
- Adherence to SOP, rules, CRM, english skills, common sence etc is not what you are used to if you are from Europe but things are improving slowly.
- About pension, I don't know but making a money transfer is very cheap and you get paid pretty much tax-free. It depends on your home country wether you have to pay tax on what you transfer home. But sending it home is not a problem. Your salary will be very good and costs of living can be kept low unless you buy a car.
- With new EASA rules you will most likely have to transfer your license to a Turkish DGCA one. That will yield problems in the future if your license is a JAR/EASA at the moment. It's a major flag carrier so from that point of view it's nice, but the Turkish CRM is famous for being Captains resource management. Chances of transfer to 777 is not that bad if your english is really good. But you need some luck.
All in all, it's a good deal for a first officer. Turkey is very different and can be really nice if you are open minded. Don't expect to be treated like in Europe where you have alot of rights and not as many responsibilities. In Turkey you have no rights and alot of responsibilities. Food is nice and cost of living is low unless you buy a car. People are very friendly and helpful but will take advantage of you later if you do not show alot of character.