The Iframely plugin takes care of 95% of cases where you want to embed something, and there's a configuration you can make that gets you the embeds, without it counting toward your limit (if you use the cloud service). For uploaded videos, I use the ns-embed one with a custom rule
I also think Nodebb need a redactor editor because basic users may not be custom to markup language.
The issue now is that the default composer and redactor composer are incompatible, several plugins that was developed for the default composer will not work for redactor. I hope Nodebb can standardize the composer for both expert and novice users.