I have always used nonverbal information when I couldn't follow/comprehend verbal information, so I think it's useful. I have found that even just having a sense of whether or not a person is expressing negative vs. positive vs. neutral emotions can be a useful thing, even if I have little/no idea of what the specific emotions are and no idea why those emotions might be there.
Nonverbal communication is just one piece of social interaction, though, so I don't know how much improving your ability to use/read it would improve your social life unless your only difficulty with social interaction is with nonverbal communication.
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"Coming back to where you started is not the same as never leaving." -- Terry Pratchett, A Hat Full of Sky
Love transcends all.