as I think a syndication of feed is not considered as duplicate content since its source is already defined. Also google has recently said that it automatically determine which content to show in SERP. If it has first appeared on facebook you will not rank for the keywords used in facebook posts. Also the feed syndication has nothing to do with your seo except it has no value on your page in terms of content.
I don't think it will hurts.Being the original content reference given as reference
I agree with the point of zabalex.
Yes, even I feel so. There is no harm caused due to same content in this particular case, but my suggestion is, use different article/content. This will add something to the profile and didn't harm the website too.