So if I Go to sleep in the evening and switch off, in the morning I can simply say something like: "Alexa, turn on the TV and play the Netflix series" or do I still need the remote control despite Alexa voice control.
It depends on the TV whether he supports it
You may have to activate the HDMI CEC menu on TV
The voice control of the Fire TV has nothing to do with television anymore, it is all about switching on and off and pressing the remote function on the remote control, for example, pause and so on
With my stick (with a somewhat older TV) Alexa can switch on the TV. Then start a video with another command. It is not possible to nest multiple commands and have them executed at once.
I found and activated the CEC control option. If I would buy a Fire Stick now I could switch my TV on and off via Alexa or?
As long as I don't have to get out of bed I talk to Alexa for 10 minutes until my TV is on.
Yes it should be like that
Not really?
When I say my google chromecast play XY on Netflix.
he turns on the TV and starts Netflix with the desired content in one go
Alexa can't execute chains of commands. However, you can write a skill yourself (if you are fit) that can do it. Then, however, only the sequence as it is in the skill (almost analogous to batch processing in DOS, if that tells you something).