[noggin]

Received my Core today
And here are some questions (sorry *g*)

1. How can i change the sensity of the air mouse. just found a menu entry, where i can activate/deactivate the remote (did not notice any difference)

It's in a different menu - think it's more allied to touch/mouse sensitivity (Android doesn't really understand the remote control concept outside of Android TV) wrxtasy will pop up in a minute to confirm. I found it after a bit of digging in Android settings. Took a few minutes of looking. Can't remember precisely where it was.

2. The latest update is installed. How about the 24p content. Does Kodi 15.2 set it by itself? Sync Playback is activated

If you have Adjust Display Refresh Rate on Start/Stop enabled in Video settings (think it's in Playback) then it should work. You probably don't need Sync Playback enabled unless you have 24/23.976 issues.

3. Netflix: Is EVERY content from netflix in 24p? or do i have to set the switch manually and every content just will be played in 24p?

Most but not all. I'd expect movies and US scripted drama and 'film' comedy to be 23.976p. European stuff may well be 25p (if you see horrific judder then disable Netflix switching to 24Hz in the Refresh Rate Switcher app) and manually switch the video output to 1080/50p (which I think you can do) and some 'video' stuff in the US may be 29.97 (so best output at 1080/59.94p or 60p)