The rich text editor I've choose, the unfortunately named WMD Editor, is also chosen to solve this problem. With WMD Editor you see the raw text you type and a live preview of what the text will look like on the page. (The live preview should help reduce formatting problems) This could create a problem with users pasting from Word, any formatting they had in Word will disappear when the paste it in the text box. I've looked around for ways to solve this problem but editors that support pasting from Word have other problems.
The issues I've encountered
1. Paragraphs separated by 3 or more returns (enters)
2. Paragraphs separated by a single return and not indented so you can't tell where a paragraph ends
3. Paragraphs indented 8 or more spaces.
4. Text wrapped to 120 characters which is then wrapped again by the browser
5. People pasting from Microsoft Word and having the user's current favorite font used instead of the one used on the rest of the site.
6. Comments having unparsed bbcode/html because they don't allow the same text you can put in journals.
7. Images being used to track users on the site.
8. Text stretching the layout
To avoid this I have chosen a consistent style for text to be displayed in. When the site is launched, all paragraphs will be in block style. (No intending, two returns between paragraphs) All text on the site will be restricted to the standard display. Allowed HTML tags will be limited to the same set of tags that markdown will use with the addition of tables. There will be no scrolling, blinking, or colorized text allowed. Comments can have the tables and links just like every other rich text field. Images won't be allowed because they can be a security risk or break the site's layout. Non-breaking spaces ( ) will also be stripped.
Comments/Questions are welcome.