I think that Erdogan can of course try to change the political system in Turkey, but do not forget that in this country of frequent revolutions. Let's hope that Erdogan will pay the price for his dictatorial tendencies.
No, and never. Erdogan can't be overthrown when he enjoys close to 60% approval. I am surprised that you posted this, after what we had in 2016 (the failed coup attempt by the Gulen supporters). That incident proved that he can't be overthrown.
It seems to me that it was not a coup, and performance. Erdogan himself has orchestrated this coup to be able to increase its influence and to deal with the opposition. Such a coup is impossible so quickly and without fighting to suppress.