As much as you like.
You can make a clip show, add videos to a movie, give it a menu, and put it on a dvd.
yes
Use the Split function to clip videos. And be careful what portions you delete.
It depends on the licensing of the clip art; for example, much clip art is licensed for personal use only, so commercial use would require an additional license.
The "_parent" object is a reference to the parent movie clip. For example, if you have a movie clip on the main time line with the instance name "movieclip1", with a sub-movie clip named "movieclip2," you could preface variables in the Actionscript in movieclip2 with "_parent" in order to access variables in the movie clip above. For example, to access "var something = 10;" declared in movieclip1 from movieclip2, you would use "_parent.something".
Movie Clip
All you have to do is search a movie or clip and click the movie or clip
It depends on the length of the clip, the audience for your resulting work, and more.
A movie clip is a single 1-5-minute scene from a given movie. A movie is a collection of scenes that tell a story.
Trying to figure out what you mean by the question. The movement from clip to clip would likely be frames.
When viewing a movie clip on the Web
You should be able to use clips of songs for the purpose of education or commentary, but there is no indication in the law saying how much is too much. The only way to know for sure if your use is fair is in court.