Yes, lots of options like this to various airports, but going the other way is not so cheap. SKG-ATH-HER for 61 EUR for example.

I think there are 2 possible scenarios with these new changes. Either they will see an uptick in demand for domestic flights, or they will see a decrease in demand for all flights.

I don't think they should underestimate the part frequent flyers have contributed towards Aegean's success over the years. Maybe they will come to regret these changes, 12 A3 flights per year for Gold is quite hefty for most people when there are easier options.