Service during the early 1920s was sporadic: most airlines at the time were focused on carrying bags of mail. In 1925, however, the Ford Motor Company bought out the Stout Aircraft Company and began construction of the all-metal Ford Trimotor, which became the first successful American airliner. With a 12-passenger capacity, the Trimotor made passenger service potentially profitable. Air service was seen as a supplement to rail service in the American transportation network.
Kefallonia was severely shaken by an earthquake in 1953 and thereafter lost its quaint gloss. The picturesque northern port of Fiskardo however, escaped much of the destruction and remains to this day one of the main focal points for visitors to the island, so is a good spot for a stay of 2-3 days. Pretty, waterfront cafés and restaurants and a cosy, folksy feel predominate. Asos, between Fiskardo and Argostoli is a west coast ‘resort’ village that pulls in its fair share of visitors and the view down to Asos from the main island road is one of the most photographed spots on Kefallonia.
The only ferry from Kusadasi to Greece goes to the Greek island of Samos. It’s a great island and certainly worth a few days. From Samos, there are usually direct ferries to Mykonos and Syros. These are very different islands that have a very different vibe – but both appealing in their own way. From Mykonos there will be direct flights to Western Europe (most likely Rome, Paris, Amsterdam, and London) though not every flight flies every day so requires some planning. Santorini would be another ferry ride from Mykonos. And Crete farther still. So you wouldn’t have time to get to either island.
Since airline reservation requests are often made by city-pair (such as "show me flights from Chicago to Düsseldorf"), an airline that can codeshare with another airline for a variety of routes might be able to be listed as indeed offering a Chicago–Düsseldorf flight. The passenger is advised however, that airline no. 1 operates the flight from say Chicago to Amsterdam, and airline no. 2 operates the continuing flight (on a different airplane, sometimes from another terminal) to Düsseldorf. Thus the primary rationale for code sharing is to expand one's service offerings in city-pair terms to increase sales.