This seems like a pretty straightforward issue of an employee doing something shady they should be fired for. I'm sure they will and the schools will put into place checks to make sure this is harder in the future.
> Is donating 'sexual favors' ok ?
Prostitution is currently illegal and I'm sure this against the most colleges code of conducts. I really can't imagine a possible future where this becomes a problem. "Come to HigherEdUniv, we accept an SAT score of 1400 or 1200 and a blow job".
> Should the same principles be applied for job promotions in private corporations ?
Sexual favors? No this is currently illegal and falls under sexual harassment / prostitution.
Giving a lot of money to a corporation for a promotion. This seems like pretty straightforward yes, companies exchange money for control all the time. YCombinator is founded on it.
Giving a lot of money to a boss without the agreement of the company for a promotion. This is shady but I've never seen or heard of this happen in the U.S. Normal corporate governance seems to take care of this issue.
> Is it ok to do similar differential treatment, for different students, for their grades throughout the study, and not just initial admission?
From a legal standpoint sure this seems ok. How long would a university exist if they did this, not very long.
> … aren't those kinds of behaviors, that are then breading the 'financial services execs that 'look the other way' and caused financial crisis of '08?
Completely different problem and set of behaviors. These types of scams involve only a handful of people and have very little impact on society. Financial crises happen pretty often and affect everyone in the U.S.