or can I keep my polish on as long as its not chipped, or does it matter?
      Answer1:If your nail polish is neutral and they look acceptable then its fine. If they are anything out of the ordinary (ie not french polished or very light in colour) then you should take it off.
      Answer2:I think it is better to be understated at an interview. Clear nail polish is best if you feel you wish to wear it, however if it is a food environment, it is probably best to have nude nails as it would be considered a contaminent.You need to look professional, not as though you are ready for a night out, and the interviewer should be listening to what you have to say, not be wondering why you have worn inappropriate polish on your nails.Best of luck with your interview.