copyscaped passed? content that doesnt use cited sources? and, are articles which are citing sources considered unique?
Citing sources is commonplace in pro writing and has nothing to do with an article being unique or not (directly). Not sure what context you're looking at, but if you mean for SEO reasons, it's just one that passes SE filters. So, partially rewriting an article would be "unique."
You can cite your sources and that is a common practice when it comes to professional writers as marketjunction noted. Even though not all articles require citation, let's say you can write an article based on your own experience doing something which is not documented, hence there is not expressly a source to cite.
No. When I'm writing news stories they do (source said, etc). When I'm writing about a personal experience that doesn't use outside data I don't.
Generally, a unique article is one that's different from other articles out there. It's possible to write from a source and still have a unique article. That's where paraphrasing comes in. Of course, if you quote a source, the quoted part won't be unique.
You can get your information from various sources and still come up with an unique article as long as the author produces a unique take on the material or applies the knowledge in an original way. Copyscape is just a way to check for blatant plagiarism. A writer could potentially spin an existing article to make it pass copyscape, but I wouldn't consider an article of that nature unique.
As far as your phrases do not match with already indexed pages its not copy past and unique. I have found one website that check plagiarism free. duplichecker.com
I read somewhere that Google looks for 50% uniqueness. However, I would shoot for 70% uniqueness, to be on the safe side.