The choir director should learn to find and give out (teach) parts. Either teach them or have someone teach them to do so. Immediately. If they can't hear or do parts, that IMO is a big FAIL in choir leading...
YES! If you can't hear, how can you correct?
Also, I think a good choir director has to have some sense of discernment. Don't drag a song out just because they do it like that on the cd. If it's time to cut it off, CUT IT OFF. Along those same lines, you might get to a part in the song that pulling on the heart strings of God...go with it.
Preparation is also key, and you must have a passion for what you do.