I almost never want the audio to get separated from the video. Is there some default setting that says assume audio and vidro tracks are "grouped" or "locked" unless I select otherwise? Group and lock don't appear to be the right words for what I want to do....?
The video and audio are grouped by default (unless you selected the "Ignore Event Grouping" button in the toolbar). If you somehow ungrouped the audio and video, you can group them again by selecting the audio and video events and pressing "g" on your keyboard.