Yes it's just general information, like the information we already provided on the primary. I believe they ask about our experience with a DO (their institution, alma mater, etc.), but other than that I think it's pretty basic. Someone else please correct me if I am wrong, but I do not think that I am.
As for the grade concern, it was my previous understanding that you must have a C or better in all required coursework. If you took an elective like Astronomy or Intro to Music or something and got a D it really wouldn't matter (except for the effect it has on your cGPA). However, while in undergraduate most university's require >C- for all classes which will count toward your degree. I'm sorry if that doesn't pertain to you or if you were already aware. I'm with you though; you DO NOT need >C- in all courses to apply to get a secondary or an interview. It will hurt your chances solely because it will show up on your transcripts and thus your application packet. I did see that you said you got a D in Bio II. If that is the case, you might have to retake depending on whether the school requires 6-8 semester hours of biology (most do). It is either retake or replace with another biology course such as Microbiology and/or Molecular Biology. You did the best thing by contacting the admissions office, so all this advice will probably end up being useless. Anyway, I hope that helps a little :/