I'm putting together an optical list for the post house, but the only way I can think to find resizes and speed changes is by inspecting each clip manually. The film is an hour and a half, so if anyone knows a way to quickly identify filtered and motion altered clips I would appreciate the tip!
If all your footage has the same specs and your timeline is set up with the same specs as your footage, you should be forced to render any speed changes and the render bar above the timeline should reflect that (will show up bright red). Therefore, if you delete your render files, anything that shows up red is altered footage (time-remapped, filtered). The only pitfall with this is that I believe some filters can be rendered in realtime by FCP and that might not get reflected in the render "status" bar above the timeline.
Not the most elegant solution but would save you some time.