Removing that amount of nodes would hurt new players more than the current state of the pricing in the game. Because starting players need the amount of nodes to get going, removing these would be really hard to start unless you know exactly what you're doing.
Making the entire map PVP based would remove the need for PVP zones and harvesters, unless harvesters could be placed anywhere. As cool as true open world PVP would be, it just wouldn't work. The amount of greifing that could be done would turn more people away.
I like the ideas, but they sadly just wouldn't work, in my opinion.