Is there any way for the AFROTC Board to know if someone is majoring in nursing; they have them register under the "general studies" category.No but very high impacted / specialized major then yes. For example, if you are majoring Nursing and receive a Nursing scholarship, you are ultimately going to be expected to be slotted for Nursing.
If you are Electrical Engineering and you put Engineering as your #4 and Space Ops as #1, you might still get Engineering due to demand.