Having lived here for 8 years and travelled extensively throughout the country I would offer the following;
1. The country is vast and sparsely populated away from the coast and big towns/cities. Riding in these areas is a pleasure. Turkey is spending huge amounts on the road infrastructure and the main trunk roads have been, or are in the process of being upgraded, to wide dual carriageways. I've often wondered why as the light traffic doesn't seem to justify the expense. Main dangers here are stray dogs, melting tarmac in high summer and dozy drivers, through tiredness and heat.
2. In big cities there does tend to be a bit of a free for all attitude. A two lane road will turn into a four lane highway as drivers vie to be the first away from traffic lights whilst nattering with other occupants and answering their mobile phones. Indicators are a fashion statement rather than a means to signal one intentions. Vehicle horns are used to let you know you are being overtaken or you have dawdled too long at traffic lights.I always drive defensively in towns/cities.
3. Speed limits for motorcycles are lower than those for cars and speed traps are very common. Make sure you know the speed limit for the type of road that you are on. The traffic police are always friendly and polite when issuing fines/checking docs.
4. Modern bikes run with headlights permanently on so no problem there. Wear a high-vis vest if it gives you peace of mind.
5. I seldom ride in the dark here. Too many stray dogs/cats/kids wandering around. Additionally, in rural areas, cars and tractors often run without rear lights though they will have headlights so that they can see where they are going!
6. Petrol stations are modern, clean, plentiful and rarely self-service.
In summary, if you drive defensively and within the speed limits you should have no problem with the odd pothole, loose gravel on a bend or farmer on his way to market.
Have a good trip, it's a beautiful country.
Cheers,
Dicky