A couple of things here:
1) What does the USB storage cage do? I would like to know before I take it out.
2) Does the adapter come with it? I see a white plug that looks like it's a part of the box set that might be what you're referring to or is it something that you order additionally when you are finally making the purchase?
If you are referring to the proprietary HP docking bay, it doesnt do anything unless you are willing to pay for overpriced external storage. I removed mine long ago and clipped the door open to allow more airflow.