Related: How should I approach editing?
RPG.se seems to lend itself to longer answers than some other sites. Because of this, formatting becomes even more important.
Before I commit to reading a wall of text, I like to know there is something worthwhile in it (and I read a lot of answers on this site). Typically, I try to skim each answer for main ideas before reading. This becomes significantly easier if there is any bold or italics.
Occasionally, I see an answer that has a lot of interesting information, but is difficult to scan. Some especially long questions are difficult to digest, even on a read-through.
On occasion, I edit posts in order to bold key points. I have even added a paragraph break or two. However, I am wary of offending someone (especially because I only edit answers that I think have excellent content!).
What are the limits of politeness? Are these formatting edits disrespectful of the author's intent?