5. If a letter mentions a weakness of mine, will the letter work against me?

Particularly if you waive your right to review the letter, ask the letter writer if s/he can write you a positive letter. If an overall glowing letter mentions one or two areas for improvement, the letter may be taken even more seriously than one that makes you sound perfect. The admissions committee is being assured that your letter writer sees you realistically and is willing to be honest. However, if the overall tone of the letter is not positive, this WILL likely count against you. If you want to see a letter because you are concerned that it may not be positive, consider asking someone else to write the reference letter!