Even cheapest TK business class flights from CAI book into K so it will be 150% flown distance.
I assume that ATH-CAI RT is positioning flight for CAI-DPS trip and ATH-CAI will take place before CAI-DPS and CAI-ATH after. I also assume that have 0 miles before first flight flight. Trip ATH CAI is paid business class ticket
I'm not sure how many miles will you get for 8 domestic segments (I assume 3000)
System will give you silver status on the date you made flight IST-DPS (1600 miles for ATH-CAI, 10825 miles for CAI-IST-DPS and two A3 flights).
From this day you will start to earn miles for gold status. You will have 10825 miles for DPS-IST-CAI and 1600 for CAI-ATH leg and miles left from silver (12000-3000-1600-10825 is about 3425. 10825+1600+3425=15850. 24000-15850=8150. It will remain 8150 plus 3 A3/OA flights as previous flight too place when you were blue or silver.
It would be better if you take at least 4 of your 8 OA flights after DPS trip. Then you will need just 8150 miles.