Right off the bat, I would like to let you know that those are some of the more expensive countries in Europe...except czech anyway...
For sure 2 months is enough time, you manage the time you have nayway you want while your away my friend, one city you might wann astay longer and another city you might wanna stay less time...it will all depend...you'll know when you get there. WWM has ton TONS of short trips abroad, and he appreciates every moment he has to spend, even though it might only be a few days, point is, use the time you have wisely, and don't have regrets about the time you do not have...
Must sees...hmmmmmmmmm...here are a couple for ya....
All the major cities are mus sees for sure, as I am sure you already know...If I had to pick some things to do and see....
Paris, Jim Morrisons Grave, Enjoy a glass of wine at a vinyard in central France
Italy: Get an Old Woman to Cook For You, Any Village
The Holy Grail, Genoa (Hey if the Genovese say its real, then it must be)
Battle of the Oranges, Ivrea ( held every year on the Thursday before Shrove Tuesday)
Open a Swiss Bank Account!!!!!
White Water Rafting, Interlaken
Germany: BMW Museum, Munich
Traditional Beer Hall, ANYWHERE!!!
Salt Mines, Berchtesgaden
Nazi Bunkers, Berlin
Enjoy a couple days in the Black Forest
These have been my picks before when peps have asked what to see, but the choice wil be your own in the end my friend!!
Don't forget about the small towns as you make your way through these countries, you will find very interesting people there, as well as people interested in you :-)
We are all here to help each other my friend!!!!