We love Scandinavia.
Technically Scandinavia includes Sweden, Norway, Denmark and Iceland, not Finland and Estonia.
I hope you aren't planning to do all this in two weeks. That is way too much to cover in two weeks.
Copenhagen and surrounding area needs about 5 days.
Norway has the incredible scenery and in my opinion best seen on a cruise. We did an 11 day cruise last month that went all the way to the North Cape. It was awesome. We visited Geiranger, Flam (we had been to Bergen before), Alesund, Stavanger, Tromso and the North Cape. Your ship goes up these amazing fjords, then you visit the ports and see even more.
The highways in Norway are in mountainous areas and slow moving. You can take some trains, especially in the south, but do it by ship is great.
You don't have to go all the way to the North Cape, there are 7 day cruises that cover the southern part of Norway.
Stockholm deserves 3 days, we only did 2 there and wished we had planned for more, then we took the train to Copenhagen were we picked up the cruise.
The Vasa Museum in Stockholm is a must see, as are the Royal Palace.
There are cruises of the Baltic that include Helsinki, Talinn, St. Petersburg, Stockholm, Germany and Poland.