Did someone say keywords? unless its automated through your plugin don't spend your time on keyword metas, or waste your time rather. After all these years its funny to see that though. They can't help with Google, Yahoo or Bing rankings but they can't hurt either.
If you are using plugins I assume you are using a Wordpress CMS, so the easy answer I think is that you use the many other plugins optimised for this and mash a few together.
Here are the main ones I use, as well as a paid plug-in that's worth the money if you do video optimisation;
Advanced YouTube Embed Plugin - Embed Plus
Facebook Button Plugin
Facebook Like Box
Google+ Author Plugin
Google Author Link
Google Plus Author Information in Search Result (GPAISR)
Like-Button-Plugin-For-Wordpress
WP OnlyWire Auto Poster
OnlyWire for WordPress [OFFICIAL]
Super RSS Reader
SEO Ultimate
PAID -
http://yoast.com/wordpress/video-seo/
You'll need a G+ author account, and an Onlywire account which needs up to forty plus web 2.0 social media accounts that you will need to sign up for...and this is just the beginning.
I won't go into each and everyone. That's for you to do your homework like an
SEO and learn what these things do. Most of what you need to understand why to mash them and how to use them will fall into place. If you have a question about one or more of them or if anyone else wants to know why and you have already researched what these plugins do just post the question.
Basically my short answer is, if you are doing what you say and adding new, unique and optimised content, you need to get that content out there to get linked to and for social media to get it kick-started.
hint; you can buy things like Pinterest links, Facebook Likes and Friends, Tweets to large networks and other types of social media injection for a job.