A. The answer to this question could determine whether or not you are going to sell your proposed book. These days publishers are adamant about authors following their guidelines exactly. Some will go so far as dumping a proposal in the trash if they see you have not taken the time to follow their guidelines. They get so many proposals these days and the competition for the few book slots is so fierce that they can afford to be selective. They will tend to take the book that follows their guidelines and requires the least amount of editing, over a better book that requires more editorial time than they can afford.
Your proposal should convince an editor that you have selected them specifically because you feel they are the best publisher to publish your book. The last thing you want to do is give them the impression that you selected them at random. Yes, closely targeting the needs of an appropriate publisher is time consuming, but it's part of your job as a professional writer. And, you can't expect a publisher to invest thousands of dollars in publishing your book if you can't bother to take the extra time to send them exactly what they are asking for. I'm sure that thought crosses an editor's mind when one of those generic proposals lands on his desk.