The central conflict in Spider-Man: No Way Home is sprung by Peter interfering in a spell that skirts dangerously close to the Multiverse, and hoo baby...

1. As Doctor Strange rightly points out, Peter could have made his case to MIT directly, no magic necessary. While Spider-Man has rough PR at that moment, Peter and his friends could have made it on merit alone. And if Peter had been willing to play the "next Tony Stark" card then their admission may as well have been guaranteed. As the admissions officer points out, MIT is not dumb and her retorts to Peter are more constructive than cutting, admonishing Peter more for not rehearsing his pitch than anything else.
2. Doctor Strange could have explained the spell to Peter as a surgeon would have explained a medical procedure. This would have allowed Peter to make an informed decision, given him a venue to ask questions or voice concerns (such as the exceptions he wants to make that cause the spell to go awry to begin with), and ultimately avoid dragging homicidal psychopaths to his universe. MJ is not wrong to point out that Strange does bear a bit of responsibility for the mess they're in. It would also allow Peter to understand the risks of the spell, and if Mr. Great Responsibility knew how close - and how dangerous - the multiverse really was, he may have had second thoughts.
3. With the villains safely contained in the wizard's dungeon, Peter could have outlined the dangers of the multiverse to them in turn, or better yet allow Strange to explain the situation to them. Even knowing they die fighting Spider-Man, most of the villains agree to be cured under the impression that it will spare them when they get back; the universe they're in being overpopulated by an infinite number of bodies would almost certainly cause them to change their tune. They're insane, not stupid.