The application wasn’t too complicated (then again, it has been about four years since I applied to one), I personally found it less stressful than the college process, and it actually is a good way to help you prepare for the actual college process.
For the better college part, I would guess you could say that, but that’s only because a certain type of people go to boarding school. Of course they are idiots here (you can never get away from them), but we don’t have the same problems and idiots that a public school has. Also, boarding schools are much, much smaller than most public schools. Boarding school does help prepare you for college, but most of the colleges I’ve been looking at (which are mainly Top 25 colleges) claim that at least half of their students come from public school.
I guess what I’m trying to say is, no matter where you go, do your best and you’ll get into an amazing college. And don’t go to boarding school just to get into a “good college”, which is a completely subjective term. Boarding school is an amazing experience in itself.
I hope that helped!