When I was young

, among orher things I used to run a political blog on blogger.
The blog was in Greek language and I didnt care about seo, as It is very difficult (and useless to me) to rank for a political thesis in google.
The content of this blog was 70% original, written by me, with some reposting from good sources with similar political views,with no junk posts.
What I did to promote it was email marketing (or spamming if you preffer) to spread my ideas to other bloggers.
This led my articles being copied and recopied again and again from various political blogs, some of them with high authority, some being completely trush, some linking back to me, most of them not linking at all, trying to present articles as their own. (In many cases, when a very strong blog reposted the article, stealed it and my blog did not get in google even when I wss searching a very unique post title I wrote) .
In terms of seo, today this blog has a PA of 53 (and blogspot's DA) and the reposting thing seems to add authority on the blog and not reducing it.
After this, I often use email marketing targeting bliggers for other websites I want to promote, and everything seems to go well both in terms of visibility and seo.
So I agree with the above members, dont be afraid of seeing your posts on other websites.