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It depends on your understanding of "similar". Sometimes similar content can look different, sometimes it won't. If you change few words on few thousand word article, it will definitely be duplicate content. Hope that helps.

Try Rank Tracer. It used to be OK when we were using it.

Simple answer - use rel=canonical to indicate which article you care the most.

From our own experience first step is to create great content with natural flow of keywords. Then we'd advise to do some external linking, followed by other activities that would lead to links to relevant keywords in article or better to article url. SERPS crawler will catch keywords that are necessary without webmaster interference (mentioned earlier by igor and james).

Once and foremost - great content with support of promotion to relevant sources. Many times before got links from sources we couldn't ask for simply by showing expertise. It's that easy.

I really doubt. This comment section seems to somehow prove it as it also uses wysig editor. I can't really see co-relation between wysig editor and hand coding as in almost every editor you can switch to source code and manualy alter anything you need.