I don't think this was meant to be an essay. :-)
(10 points) Grammar, spelling, clarity
Not really sure what you want here, but I’ll take a guess. When it comes to the importance of grammar and spelling it’s important I mean if you are talking to a group of well educated men and women or older folks whose grammar was driven into them, then if you have bad grammar than the person will more than likely dwell on the fact that you just said ain’t and not pay attention for a little while. Good spelling comes in handy for your notes, you don’t want to mean disciple and spell discipline; similar yes, but two totally different meanings. Something like that can ruin an entire point. Clarity is also important for sermons because vague sermons are never easy to deal with; congregations want to have a definitive idea of what is being preached on and they want a conclusion. I know that when my youth pastor at home preaches and he leaves it hanging I feel very frustrated. Clarity could also relate to how you speak or preach, in that case it’s very, very important. It’s important so that the congregation can understand what you are trying to tell them from God, as a minister you have a very important job, there’s no getting around that. Why not speak clearly and with clarity so they can understand what you saying: whether that means working on your speed, working on your annunciation, or whatever it may be.