#1 - Don't embed video you don't own onto your site, link to the video instead
I understand where you're coming from on this, but I'm not sure I fully agree with this point. It may well be an issue of fair use and of context. Whether you embed may depend on how the original video was intended to be shared. If you are, say, an electronic widget site selling electronic widgets, embedding someone else's demonstration of the product, I agree, is very bad form.
On the other hand, if you are a forum like WebmasterWorld, where you often discuss new developments in Google, it's completely natural to embed Google's video announcement of such a development, which is intended to be shared. It would not be appropriate to embed and individual SEOs analysis of that announcement. It's a point certainly worth further discussion.
#2 - Don't link to just one video, linking to 2-3 is better.(more on why this works below).
Ditto with embedding the highlights, as in #4... but a page with simply a sequence of such links without substantial new viewpoints expressed, can I think get you in trouble.
A sequence of excerpted embeds, IMO, would perhaps be worse. Again, it's a question of how much new one brings to the material.
This is true of written material as well as of video. I also believe that "mixing things up", so to speak, to create lists that might get around Fair Use, can backfire.... From what I've seen of Google's recent AI capabilities, Google is now capable of consolidating algorithms and nesting them.
When embedding, IMO, or in posting an new video... always provide an indication of the video's length. Additonally, if you embed the video, make sure that the timeline of the embedded video is accessible to users. Making the timeline invisible, IMO makes video extremely user-unfriendly. I can't imagine watching a video not knowing whether it was 2 or 20 minutes long, or without being able to stop and start it.
My background in film/video and audio makes me compulsively include "trt" (total running time) on all elements. As time has become a premium, notice that many social self-publishing sites like Medium and Substack have followed in the same vein by providing estimated reading times.
Regarding the mechanics of YouTube embeds, here are some references and thoughts about implementation that I've found helpful.
YouTube Embedded Players and Player Parameters https://developers.google.com/youtube/player_parameters [developers.google.com]
Making YouTube Videos Resize With Responsive Design April, 2015 https://www.webmasterworld.com/video/3006089.htm [webmasterworld.com]
The responsive embed thread is over seven years old and may be dated, but I haven't seen anything newer on the topic. If there is new material, I'd love to see it.