As for the CD, I wouldn't play it in a drive that doesnt pop out (the kind that you just put the CD into like on Mac's) but any other pop out CD drive should be OK.
Not trying to be discouraging, but clinical experience is a big thing that Adcom's look for in an applicant. I think the average applicant has around 100+ hours of clinical volunteer hours, so you might not be competitive in that area. I guess I would send in the secondary now, tell them that you are planning on volunteering and, like you said, send an update letter when you've gotten some hours in. So does that mean that you don't have a LOR from a DO or MD yet?
Good Luck