Does this seem like a good itinerary? Is it feasible for me to take ferries until I reach Tallinn, and then take trains or busses?
Also talk about your experiences in these cities. I'm still young and would like to meet people and have fun nights out. I've heard that Helsinki is "boring" but I don't care, I want to see it anyway.

4 nights Stockholm
2 nights Visby
2 nights Helsinki
3 nights Tallin
3 nights Riga
2 nights Vilnius