I've been searching this but I have been unable to search for the right terms.

At this time, automatically filling in the timeline is not helping me, it is only a hassle. When I create a new layer, I start with a frame that is full for entire length of the timeline. I'm tracing over a video. So creating a new layer means I have to go and remove 6000 frames. How can I just stop this from happening?

Oh, while I'm at it, let me go ahead and ask. Is there not a shortcut key to hold while drawing a line to toggle snapping? I have searched and only fount Ctrl-/ to bring up a snapping menu. Well if I'm drawing I have times where I want it to snap and times when I do not. Is there a quicker shortcut to toggle this?