I think it's the approach one takes mentally. It's in your mind that you'll retreat to, to decide where you want to go in life.
I agree, not all gung ho applicants make it. But that's not because they're gung ho, it's because of where they're drawing their strength from. I had a classmate who was "hard for the Guard." He had been a big shot in JROTC. His father has been a senior enlisted member of, either the Coast Guard or Air Force, I think Coast Guard (they all look the same.... right?)
Anyway, as they beat into him, they would ask "Swab John Doe, why do you want to be here?" and Swab John Doe's response was typically "Swab Doe's father was a master chief in the U.S. Coast Guard, and Swab Doe wants to be exactly like his father!"
We heard this EVERY day. Swab John Doe was a nice guy and I roomed with Swab John Doe during swab summer. He instruced me to some kind of sponge, to "shine" my leathers.... but in the end the sponge ruined my shine.
At the end of the day Swab Doe didn't make it through the first year. Being there to be like someone else, or to impress friends and family, or to "try out" will only get you so far. At some point the REAL reason your there will confront you... and you'll make a decision, then and there.
I think it's prudent to understand your commitment requirements, if you owe time and money, and how hard it's going to be. I'm not sure if that should be your PRIMARY concern. You would be better served understanding how the school works and what you'll have to do AFTER graduation. The primary questions that you have posed here, should, in the long run, be footnotes to a bigger theme, how to go to CGA and graduate.
"Trying out" is getting a $50 guitar, strumming it a few times, and putting it behind the door, never to touch it again. "Committing" is getting a $3,500 banjo, paying for lessons, and working at it every week. At the end of the day, both are try outs, but one displays a real commitment to the endevour. And it should also be noted, the five-string banjo is far superior to the guitar, but that's another lesson for another day.