Instead of dragging the video file into an audio track, there should be an 'import video' command that would detect the video's frame rate and create a horizontal split (similar to the split before return tracks) in Arrangement, which would yield two timelines, where the new one would be frame based.
This would allow tracks in the frame-based timeline to be synced to the video and tracks in the ordinary timeline to be synced to Live's regular BPM-based grid, so that tempo changes wouldn't interfere with timing-critical audio. The two timelines/sections would be independently scrollable and collapsible.
I believe this would be a very innovative and intuitive solution to a problem that many of us have experienced when making soundtracks for videos.