One has nothing to do with the other, I'd sugest reading up on what the quality score is and how it's used. https://adwords.google.com/support/bin/answer.py?answer=10215
Not at all, if you only bid on those words and your clickthru rate is decent - your quality score will be just fine. A bad quality score has to do with how relevant your website is compared to the term you are bidding on + your CTR.