Itunes adds all movies to my itunes movies folder (not the actual folder in the filesystem, but the one inside itunes), including movies from trash and personal stuff I don't want in itunes. How can I limit the movies itunes display to the one's that are actually added to the library and/or "reside" in specific folders?
iTunes is going to display any files that are in its library. To avoid displaying files, don't import them into iTunes and don't use iTunes as the player for those files because they will be added to the library collection. To play those files use Quicktime Player or a third-party solution like VLC instead.
You can also disable iTunes's copying of files into it's own folder structure in iTunes > Preferences > Advanced, but this will apply to all media types and, in my experience, is a less-than-optimal way to use iTunes.