Oh my gosh
How are you traveling between all these places?
I mean this sincerely- do you LIKE spending time on planes, in airports, on trains because that is what you will be doing.
You don't have enough time anywhere. Do you think you will never return?
I have been to all those places and they all deserve far more time than you are giving them.
I'd drop at least half of your locations.
I encourage you to write down and be very specific- how much time you actually have in each city and what you think you can do/see.
I believe you are underestimating the time it takes to change locations. Add up packing up, checking out, getting to train or plane, travel time then getting to new location lodging, checking in and getting oriented.
Repeat that whole process for every change in location.
Berlin and Prague are huge.
Assuming you are flying in to AMS from US your first day is jet lag so that leaves just 2 days to sightsee.
Then fly to Berlin half the day spent getting there, leaves 2 full days for sightseeing.
Prague to Vienna will take more than half a day leaving you just an evening in Vienna. Get up next morning to move to Venice.
You see where this is going?
If It's Tuesday, This Must be Belgium comes to mind. ;)
I'd say drop Italy completely and give everywhere else those nights. Or drop all but Amsterdam then to Italy and drop the others.