Playlist - The good and the bad

Overall I agree with your assessment except for your first bullet point under The Bad. You CAN reorder videos and insert videos in-between others. You have to add a column to the list for ordering where you assign a number to the videos. Then you have to update the Playlist view to tell it to sort by that column. Once you do this, then you can add new videos and adjust the numbers to add them at the beginning, the middle or the end. I would recommend using increments of 10 (10, 20, 30, etc. rather than 1, 2, 3, etc) if you anticipate adding videos in the middle of the list.

I think we are all going to find that once the new formats for the highlighted content web part arrive that allow you to play the videos inline (carousel and filmstrip) that this will be the way to go because you can configure it to pick up videos from multiple sites using managed properties (which is advanced configuration that might require you work with your SharePoint Admin) and it can automatically update the order depending on your requirements.