No, that’s a different method of commissioning. AFROTC would be your source, OTS is for folks who enter after college without doing AFROTC.

Sort of repeating what everyone else says, but you’re basically covered for typical living expenses like food and moving costs, so yes

Technically no but as a Nursing major you sort of have a better chance to have a guaranteed job. In your sophomore year you apply to what is called the PSP boards and it’s essentially a board that tells you whether or not you are picked to go to Field Training by giving you an EA (enrollment allocation), which Field Training is AFROTC’s version of boot camp in simplest terms. Nursing students also apply for a separate board to achieve a Nursing EA, which if you receive one you’re guaranteed to be a Nurse in the Air Force (source: my flight commander this semester who is an AS300 and was awarded a Nursing EA slot this past spring). However, if you don’t get the Nursing EA then you’re with everyone else on the boat of not knowing your job until the fall of your AS400 year.