Is it possible to obtain an order for ultrasounds that is not limited to only one ultrasound so that a patient doesn't need to get a referral each time?

Yes. Ultrasounds often include multiple organs, so it should be possible. All the best.
Yes but depends. Ur dr can order an ultrasound to evaluate different organs but needs to have a specific diagnosis to justify each exam. Sometimes an ultrasound tech or radiologist finds something on an ultrasound and recommends another ultrasound in a few months to see if anything changed like an ovarian cyst or needs aspecial ultrasound like a sonohysyrerogram to get a better few of the uterus fot polyps.