ACNP clinical rotation suggestions

I am in the process of setting up my ACNP clinical rotation for next year. All of my experience is in cardiology which is what I want to focus on when I finish (I think). Because of this, my program coordinator does not want me to do any cardiology rotations (until my final 8 week intensive clinical) but rather focus on things I am not familiar with. I know she is right, but I am really scared to step out of my box!
Anyway, can anyone suggest rotations that they found to be very helpful. We have a big dialysis/renal population where I live, so I'm thinking that should be one. I need to do Internal Medicine, and I'm thinking ER... maybe Pulmonary or neuro?
Also, we only have 10-12 days in each rotation. How do you learn everything you need to in that short amount if time? How can I prepare myself before each clinical and how can I make the most of that time?

Thanks for any advice!