Build include unused assets and size is too big

Hi to the whole community, I present some problems that I can not solve: when compiling a scene unity included assets that are not present in the scene and the resulting files are much larger than necessary, when I select the scene and tell unity to select the dependencies to be exported as unitypackage and create a new project I see that lack many scripts. I created a short video that illustrates better than my poor English that you can see on http://www.kreative3d.it/Video/builds_size_problems.php

Monil