Let's examine some of the things you have proposed a little more closely. Sorry to be negative, but this just isn't a realistic plan.
Amsterdam Day 2 [Cycling in Country Side, etc,.] Don't expect the weather in December to cooperate, unless you don't mind cold rain and fog. You will probably even have trouble finding a business that rents this time of year.
Amsterdam[11.00pm] to Berlin [10.00 am next day] I looked at the Deutsche Bahn website to see what this would involve. Most overnight connections involve multiple transfers, and long waits in the middle of the night in small train stations, like Venlo and Enschede. Expect to arrive in Berlin thoroughly exhausted, and from what it looks like, you're planning on another overnight ride the very next night?
Berlin [10.45pm] to Munich[9.38am next day] There are sleeper cars available, but you still have to make connections. And if you've never ridden in a sleep car before, the experience of the plurality on this website is that it's very difficult to get sufficient sleep on one of these.
Munich Local+Castle Visit [11.00am to 10.pm] stay at Munich If you visit the castles near Füssen, you won't have time to see much of anything in the city. Most businesses, including many restaurants, will close early for the holiday.
25th Dec Travel day 5
Either Salzburg [Austria] or Anywhere inside Bavaria - Bayern Pass 8 euros [6.00 am to 11.00pm] Little will be open on Christmas day.
Munich [12.00am] to Tours[7.00pm next day] Once again, no direct trains and no sleepers. All connections involve lengthy stops in the middle of the night.