This thread is starting to drift pretty far from the original topic. It would be better to create a new topic.
Premiere Elements doesn't provide a way to toggle a track off and on. Tracks are always on. You can, however, use the "enable" command to turn specific clips off or on. The "enable" command is a toggle, on by default. There is no keyboard shortcut assigned to "enable", you get to it from the menu by default. But, you can edit the keyboard shortcuts and assign one. I'd recommend assigning a shortcut. "Enable" will work with either a single clip, or a group of clips selected with the lasso. Select the clips, then use the "enable" shortcut to turn them off and on as desired. Piece of cake.