Meh, I disagree with your theory about using less tags. You should use all 500 characters for optimal results. There is no proof that likes/dislikes does anything to the SEO. I’m sure that is more for the content makers info and viewers warning. The description can be up to 5000 characters. Best to post your other video links. You have no proof of anything, noone does, we can only guess how youtube seo works..
3) Youtube Description - When typing up your description for all of your Youtube videos you have a maximum of 5,000 words so use them effectively and pepper in your keyword in the description along with other related keywords to your Youtube video. For example read this entire description and you will see the "video optimization" strategy that I use to rank this video on the first page of Youtube.
Google’s aim is to provide the most relevant result for any given query. Their entire business model relies on them being able to do this, consistently, across hundreds of billions of searches. For that reason, they’ve invested heavily into understanding the intent of queries, i.e., the reason a person typed a specific thing into Google in the first place.
Brian, When a person subscribes to your YT channel as a result of watching a video, does it matter if they subscribe while Watching the video, or after the video is finished? What about subscribing after only 1 minute of the video or half way through? Does the timing matter? (You had mentioned if they subscribe after watching one of our videos it helps the video rank. I have known that but always wondered if it helps if the video is finished or not?)
Link roundups are selected and organized updates from bloggers that link out to their favorite content during a given period. Roundups are mutually beneficial relationships. It’s really hard to curate content as it involves a lot of work. The bloggers creating these roundups are actively seeking content to link to. You can land links in bunches. Over time, you will gain roundup coverage naturally. After you pitch the blogger who curates the roundup, you should connect on social media. That way, they’ll discover your future updates naturally. I’ve gained some backlinks from link roundups.
It appears that the reason this page from a little-known website is able to rank amongst the bigger players is that the content itself is more focussed. It talks about how to name images for SEO, whereas most of the other pages are more general guides to image SEO—which all presumably mention the importance of naming images correctly, amongst other things.