I've been working on a video editor for this use case: https://github.com/wong-justin/vic

Interesting approach, i like the aesthetic. When you say 'add audio' is a big task , does this mean the videos after cutting up don't have audio, or just that the preview doesn't have audio? the latter wouldn't be a problem for the use case of slicing up home videos. I have the same task as parent, might have to make a weekend project out of it.