Is it possible to install iMovie 9 on El Capitan

Not sure if anyone is still looking for the answer to this but as far as yosemite is concerned these answers are wrong. You simply drag the clip or movie into the timeline as normal and click either the entire clip or section that you want and then you click on enhance. Once you do that you now make sure to click on the video camera icon and the option for Stabilize Shaky Video will show and you can select it

I wouldn't say it's for no rhyme or reason, obviously,things sorted chronologically will always be easier to find. But this is just a slight overlook on your part, very slight. You can create a new project with the following:

1. clicking on the 'Add' icon in the topbar or pressing ⌘+N.
2. Create with whatever theme you seem fit.
3. Name it whatever suits you, and select the corresponding event your creating a movie from.
4. This will automatically add the project to the same year or folder the event is in (keeping things together, more efficient workflow)
5. You know if an event has a working project if there is a movie slate next to it's name.

1. Is a fast link to your movie.
2. This is where you cut/exclude/split and select certain clips to drag-n-drop into the timeline (#3)
3. This is your working timeline, anything you've added to the movie will display here. All transitions go here as well.
4. Self-explanitory

This is a very very fundamental tutorial, there are thousands of features packed into iMovies you might have to review their own tutorials here : http://help.apple.com/imovie/mac/10.0.6/