I preffer the edit button over the preview button.
There is probably some deep routed psychological issue at play.
I do think that there are plenty of times when the same word can be used twice in a sentence, particularly when dealing with pronouns of course but oftentimes repetition of a word is a very effective communication tool.
I re-read paragraphs as I write them and although I usually miss spelling mistakes at this stage I do find myself removing an aweful lot of commas. It seems to me that most people write in a very stocatto way by typing out a series of thoughts and comma seperating them but natural speach flows with less stops, so I tend to go back over what i've written and remove most of the commas.
Long sentences rule.