20 Questions: Energy

[NeotrekkerZ]

As a possible category to send to Cameron,

"If all energy is only borrowed, and you must one day give it back," how do the Na'vi view what goes on to be with Eywa after death?
Do they have different concepts/views for spiritual and physical energies?
For physical energy, do they distinguish between, say, energy from sunlight, energy from fires, energy from food, energy it takes to run through the forest all day, etc?
What about bioluminescent energy and how it relates to the signal transduction in the trees?  (Fancy way of asking the mechanics of the "footprints" they leave when moving through the forest at night)
Is there a relationship between their concept of energy and atokirina' as they place one with the dead woman in the burial ceremony?