If you’re contacting your regional admissions officer for a (highly-selective) school about something regarding your application, would it hurt to mention that they’re your first choice? (My parents wouldn’t let me apply ED, but I won’t say that)
It won’t hurt, as long as it is your first choice, or at least a top choice; they are certainly not holding you to it.
I don’t see why not!
My guess is that they’ll take it with a grain of salt.
It shouldn’t hurt, but it probably won’t help either. Highly-selective schools have many applicants that would much rather go to their school over others.