v3

I updated to the new version and the addon doesn't seem to work anymore.. no selections, no Action bar or Icon button. I hope this will be fixed.

OLD REVIEW

v2

What a good addon! It finally allowed me to split YT playlists with 400 elements (they became slow to manage) into smaller ones. The option to multiselect a range with few clicks is a godsend.
It works great, except for some minor issues: it messes up the order if the list isn't fully loaded or updated (refresh it often), it cannot move private videos (they could return public), it cannot drag selections inside the list (only moves to top\bottom).