Do you think that a neurosurgeon right out of residency (without any training after that) would make more than a general surgeon right out of residency (without any additional training)?
Ummmm, yes. But the 2 fields are completely different. And if you are deciding your specialty based on money, you should really second guess your decision for medicine. You can make lots of money in other fields.
Or do just about all neurosurgeons have to do a fellowship in something after they finish residency?
No, a fellowship is not needed. Usually a fellowship is for those who wish to do academic neurosurgery.
Also, could you explain this PGY-1 year to me? Is it like a required prelim year like the general surgery year for orthpedic surgery residencies?
Yes, its the same prelim year as the others.