D7000 HD video format - can each frame contain metadata? In fact the question is the other way round:

I shoot a HD video with my Nikon-D7000, and along the way things happen, such as I change zoom, focal length, light levels change such that the D7000 adjusts its sensitivity during the recording...

Is all this data available for reading somewhere, and if yes how?

I could not find the information on regular websites (Nikon's, www.imaging-resource.com, general google search).

I tried exiftool, but it seems to only show general metadata that is true for the overall video recording.

So is this data recorded somewhere, and can I read it on my Linux system?

Any answer or hint appreciated.
No. Standard video formats do not work like that and the D7000 is no exception to this.  Conceivably it can be done but I am sure it is not on anyone's priority list. I worked for 9 years on video processing and rendering software and there are more important problems to solve. Indexing and managing that data would also become a problem. When working on functions that process video from a series of still images, it makes it vastly simpler to assume the metadata of the first frame applies to all subsequent ones.

Obviously I understand why it would be desirable but this is the same on all cameras. GPS is another perfect example. On cameras with built-in GPS, only the location of at the time video recording starts is recorded while you may be shooting from a moving vehicle and cover some ground while recording.