@kochamkluski 'Attention' could definitely be a name for the need. I went on a thesaurus spree and found these words that could describe the needs:
Acitivity (as in Spooky acitivty, spiritual activity)- it would be what you describe as attention, but it's more neutral meaning would apply equally to good and neutral ghosts aswell. It motivates the ghosts to try to interact with the living world, either by creating chaos, or creating peace, or simply be mischievous (neutral).
Ectoplasm - The the energy which ghosts are made of, without it they dwindle, become invisible and powerless.
I love the idea of their death giving them powers. The question would be how they would affect neutral ghosts, or if neutral ghosts should even be a thing. I like the idea of having alignments though.
Some parts like funerals could definitely be patch worthy, but I just want it as detailed and complete as possible. :)
Btw I think perhaps we need a third need that is the ghost equivalent of hunger, except it's not for food, but something else. What do ghosts eat?