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Ideally the posts would only show in the community's space. It would be something of little interest outside of the community.

I'd prefer having a resteeming (retweet or sharing) option to share what is inside communities to your home page (blogger's section). Also, I'd add a new tab called community where posts and comments go to that tab. Steemit currently has Posts, Replies, & Comments. A 4th tab could be Communities. A 5th tab could be hashtags. A 6th tab could be top trending, the best of the best of your posts, comments, etc. A 7th tab could be Reviews, as in feedback or recommendations like a guestbook where people write notes about how they know you or what they think about you, etc.