I'm not a power user. I know lots of power users and I think they're cool, but I never have much time to learn a lot of editing shortcuts. Consequently, I don't edit as quickly as is possible. It doesn't bother me. Editing is more than speed in executing commands. Professionals benefit greatly from working exceptionally fast, but I haven't found speed as important an editing skill in my personal video work. Shortcuts will come in time, as you find your own style for working the controls.
If you use a mouse with great dexterity, you might do everything with the mouse. Open files, play video, shuttle around. Grab tools and make edits. I think this is a good way for a beginner to first experience many of the editing toolsI started this way. You can do this, but from time to time you will still need the simple hunt-and-peck for an odd keyboard item.
And as time goes on, you realize that some tasks are easier (or more logical) to perform with your fingers on the keys and some are perfectly easy with a mouse.
Playspeed vs. Nonplay Speed
Press Play on any VCR, CD deck, or other audio or video device, and the machine runs at "playspeed." Fast forward and fast reverse are examples of "nonplay speeds," as they are moving the media in unusual directions and velocities. When you edit, you will learn to live with video and audio played at many nonplay speeds (from very slow creeping or stepping, to high-speed scanning), all of which are important depending on what you are doing. Playspeed reverse, a special case where the video moves in normal playspeed but backward, provides almost as much information to the editor as the more familiar forward direction.