When Charles tells him to stop studying, I don’t think it’s about avoiding consequences. It’s Charles trying to have an influence on John. The antagonist should be against John being seen for his genius instead of his crazy, Should prefer, perhaps, that the world not get a chance to learn or experience Johns true genius. I’d say Parcher definitely wants John to reconsider taking his meds and ignoring them.
Charles is more difficult, though. Maybe through offering John pizza and beer, he’s trying to get him to avoid coming up with that new idea? That doesn’t sound right.