So I have to stop the raspberry if I want to send coins via the windows core. ?
Yes. Because of the lock files, Bitcoin Core does not allow two different instances of the program to use the same data directory simultaneously. You may also experience some issues with the files if you do use the directory. On my computers, if I use the blockchain from my Windows PC from a Linux environment and vice versa, it always requires a reindex of the blockchain. 
Topic: Share a local Blockchain possible ? (Read 717 times)
So I have to stop the raspberry if I want to send coins via the windows core. ?
Two cores can run on the same data, if they're not on at the same time. If your NAS is setup in a way that it appears as a drive letter on your computers, you can use the datadir command to set a directory for Bitcoin files.
And yes, you can run a node on a Raspberry Pi 2.
And yes, you can run a node on a Raspberry Pi 2.
Hey, I have a question to the Bitcoin core genies here 
.
So I think about if it's possible to run a full node e.g. on a raspberry pi 2 and save the Blockchain on a NAS.
Can I use these Blockchain on an other device e.g. a windows system for my Bitcoin core there, so I don't have to download it again on these system.
I hope you understand what I mean.
I think about problems if there are two cores running on one data.
I hope someone can help me.
Greetings
.So I think about if it's possible to run a full node e.g. on a raspberry pi 2 and save the Blockchain on a NAS.
Can I use these Blockchain on an other device e.g. a windows system for my Bitcoin core there, so I don't have to download it again on these system.
I hope you understand what I mean.
I think about problems if there are two cores running on one data.
I hope someone can help me.
Greetings
Jump to: