[diarrhea]

> Do you have any suggestions on how to get into more challenging lectures when the previous ones are prerequisites, and cannot be tested out of?

Not much you can do. However, even university administration is just people, at the end of the day. It's surprising how much can be achieved and how many rules can be bent favourably if one simply asks nicely, or has the right connections. That said, you'll need some proof that you're capable of skipping classes. "I find it easy" wouldn't do.