If you want to talk about replacing jobs which are done more effectively by software, managing scarce resources to maximize utility and happiness seems like a pretty good candidate.
Hard to understand what you mean. It's not like the current resource managers are trying to maximize happiness, but just lack efficiency. Just the opposite - the majority of ambitions, rich, powerful people in the world are putting tremendous efforts into extracting as much resources from the poor as possible.
Considering how far the research into EEG has gotten the line between you and the computer will eventually blur out.
I think it's more likely that there will be a massive war and the survivors will be peasants again.