Animate2: Walking back mistakes? Help!

Hi all. Been playing with Animate2. Predictably, I'm screwing up. I'm not using Aniblocks at the moment. I'm trying to create movements and probably eventually going to create Aniblocks out of it. Anyway, I've got a subset file where I want to start over from the pose on frame 0. The problem is, no matter what I'm doing trying to delete subtracks or keyframes, it doesn't work. The figures still move and the camera pans elsewhere. Still all kinds of crazy motions once I hit play. Things aren't exactly intuitive here.

To be clear, I want to delete everything the camera does and everything the figures do after Frame 0. Once I do that, I want to be able to hit play and NOTHING MOVES. After I do that, I'm going to do the motions, keyframes, all that. How do I do this? How do I freaking start over???