Concerning this part of your reply.
About the “Others”, Google categorize the social network in “Other” category when the actual name of the social network is not available or Google can’t identify it, it isn’t the combination of referrals and direct visit.
Please check again,
From my site’s stats, The “Other” under the Social Networks tab is a combination of “Search Engine”, “Referral” and “Direct” visit.
Not just one site. I have this plugin activated on my other sites.
I can provide you with screenshots if you doubt.