Not necessarily. They'd have to provide enticements that give advantages to those who stay on property and right now, other then EMH there are few.
That doesn't make sense. Add more resorts to increase park population, but increase price to decrease park population.
Doubling the prices would be disastrous. I can't speak for everyone but I for one would stop going, and tbh, I know of others who would rethink their plans. Doubling the price will certainly cut down on crowds, but it will also make put Disney out of reach for many families. As a for instance, Disney has value resorts for a reason, they're catering to people who cannot (or choose not) to spend 600 dollars a night for a bed. Many people have limited funds and are very price sensitive, doubling the price will only hurt Disney.