Sarandë - must see/do?

Hi! Me and my friend are visiting for a week from Sweden. We have so far explored Sarandë by foot, figured out how the public bus system works(!!) and went to a beach in Ksamil and today we went to the very fascinating and historic place of Butrint. Tomorrow we have a guided tour to Gjirokastra and Blue Eye. After this we have two more days - what can’t we miss?! Hit us with all ideas fit for a reasonable budget. We would like to see and learn as much about the country/area as possible rather than partying. We have a pretty gorgeous view from the hotel, is a trip to Lëkursi worth it (reviews seems to differ). Also we have eaten some pretty fantastic food already, but thankful for any advices on places to go!

We also have a question: Most beaches are private and you pay a fee. We mainly meet other international tourists there (we think from overhearing languages). Where do the Sarandë citizen go swimming during summer? Hidden amazing free beaches?

Thank you!