Ditto to what Darius said.
Disposition answers “where should this patient go next?” Disposition and follow up (e.g., “return to clinic in 2 months” or “admit to hospital”) will most likely become attributes of the encounter in the future. Using obs is a reasonable workaround for now.
Referrals (also called consults) are requests (i.e., ordesr) for the patient to be seen by another service. These are orders just like drugs and tests. For example, I might evaluate a patient for shoulder pain and a rash, order a drug to treat the rash, order an x-ray to evaluate the shoulder pain, and write to referral orders (one to dermatology to follow up the rash and another to physical therapy to evaluate & treat the shoulder pain).