My brother is currently in his third and final year in USN and is graduating in June of this year. I will say that yes it does require a lot of studying time especially during the second year. I can't say anything about how hard or stressful it is to obtain 90%; however, you do have another chance of taking the exam again on Monday after Friday and another time in the summer if you fail it.
Many people drop for "personal reasons" out of the school and these numbers are not included in the passing rate in the brochure that they give you on your interview day (it's something like 98% I think I dont remember) so numbers do lie. I have heard of some of my brother's friends who dropped because it was plainly too hard and sadly of
a suicide during the first year I think. I am not giving out any names as it is inappropriate and not trying to scare anyone... they say other factors may have been included.
So yes, it is hard... it's a 3 year pharmacy program! But they say the third year is the easiest... and I agree as I don't see my brother studying anymore... he's just playing video games and other useless stuff haha