International students are allowed to stay over the summer. All students have that opportunity. You have to register for summer classes just as you do for classes for other semesters and the same financial aid applies. My daughter has stayed for classes over the summer. It is a lighter course load than during the regular semesters. For that reason, you work more hours at your job. She has worked 30 hours a week during the summer, but the students also get paid more per hour during the summer.
It is rigorous. Some classes are easier than others, of course, but all the professors have high expectations. She has had some professors say things like, if you took this class in high school, forget what you learned because this class will be much more than your high school class even if it was AP or honors. During her freshman year she had professors say, you will not get an A in the class, you donāt have the skill set to get an A. She took it as a challenge, and did manage to get an A in one of those classes.
In the academic universe Berea is known for grade deflation. My daughter is on a sports team and graduating seniors who have applied to grad schools or medical schools have told her that grad schools have told them that a B at Berea is an A at other schools and on down the line as far as grades are concerned. I know it is anecdotal information but everyone she has interacted with has told her the same thing.
You should also be aware that as far as jobs on campus are concerned, the first year they give you a job, you do not have a choice where you work. After freshmen year and for summer, you have to apply for and interview for any position you want, just as you would out in the world. After every semester you get an evaluation of your performance by your supervisor. At the end of your time at Berea you leave with a work resume.