You sure you want to lock the tracks? If you want to turn off the “Auto Track Selector” on multiple tracks, “Shift Click” will turn them all off or on (but only all video or all audio separately. If there’s a way to turn all on and off both Video and Audio, someone let me know. It’s hard to believe that they didn’t program this). “Option Click” will toggle all tracks on and off so that the track you’re clicking is on when the others are off, and vice versa (but once again only video, or audio depending on which kind of track you click).