Video Editing in Motion
I have a 5 minute video clip in FCP. I imported it into Motion. Once in Motion, I realize that I want to trim 15 seconds off the 5 minute video clip. Can i do that in Motion? :-)
Motion isn't really designed to be a video editor (that doesn't mean it can't be done). The workflow just isn't as "pretty" as a regular NLE.
If you're trimming 15 seconds off the ends, you can simply set In and Out Points. Move the playhead to the "trim" position and type the 'i' key to set an In point or type the 'o' key to set an out point.
If you need to cut 15 seconds out of the middle somewhere, move the playhead to the one of the ends of the "edit" and go to Edit (menu) > Split. You will get two "tracks" of video. You can either set In/Out points for the second clip and move it to fill the gap, or you can simply move change the layer order (below the original) and move it left to obscure the 15 seconds of clip you want trimmed.
The group that the clips are in becomes your new "complete clip" object. If you need to add filters or make other transformations, you will use the group folder/layer instead of trying to manage two or more individual clips.
If you'd like to make a keyboard shortcut, open the Motion > Commands > Customize dialog. Search for Split. Select Split in the find list and type Option-S (I happen to know it is available). Save. [Option-T is also available if you prefer not to use S.]