7 european cities, 15 days, Madness in transportation!...Possible?

Alright, These are my destinations really that we wanted to visit. I can manage the accommodation but what I am really confused is how can I transport between these cities to the other, shall I get the global pass?. I read some people recommended against telling me you will end up paying alot for the reservations and the sleeping train….

Also are flights better for some of those trips? Please help me… I dont know what to do and where to start…

I was also hoping to visit finland (Helsinki) but I dont know will that be possible or will it complicate stuff more?