Hiking in Greece is challenging - often a lot more challenging than it would first appear. The main issue is fluid intake. The climate is so dry, you need A LOT more water than you think. Hikers are often unprepared and need to be rescued. I would say, unless you have a lot of technical experience hiking in different conditions and know how to be fully prepared for a hike, I wouldn't do it. However, it sounds like there are options to make this hike easier, which sound like they're worth exploring.
Greece has some of the most beautiful lighthouses I've ever seen! I love this one in Kefalonia The Lighthouse of Saint Theodoroi is located in the village of Argostoli which is also the capital of Kefalonia
If you're a wine lover, you must visit Domaine Foivos winery in Kefalonia!! Check it out: http://www.domainefoivos.com/en/ If you've been to any other wineries on the island please let me know I would love to visit and see what the others are like