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Nope. Using Google+ as intended may deliver positive results for your site, though. This is a nice article: https://moz.com/blog/google-plus-tips-seo

Julie is absolutely on the money; A lack of comments on blog posts will not harm your ranking (though a lack of traffic and engagement might). Getting your content shared and linked-to is where you should focus your attention; build great content and engage within your niche/community and you'll reap the rewards. Opening your comments up to the world will see you bombarded by comment spam. If your content is engaging enough that genuine visitors feel compelled to comment then the odds are it's the kind of content they would share. If you feel you are denying them a voice by preventing access to comments, perhaps you should consider a forum? Good luck.

In my opinion, 80 to 100 words is really really skimpy.   You would gain more by increasing the quality and detail of your post than by changing the number of external links.   Google is probably going to put more emphasis on your content and how your visitors respond to it than they will put into evaluating your external links.  In addition, I think that you will gain more from Google if you have highly-related, high-quality content on your own site and are linking to that.

Sidebars are fantastic. They are great placed to add photos that are relevant to your content, great places to display ads, great places to promote your best content and great places to promote related content.   All of my sites have a sidebar that is right-sized for skyscraper or rectangular ad units.