The reason we have such technologies today is cause we manipulate our resources with full control.

Now on Pandora, if you pluck out a single tree leaf, Egwa will know... and probably send a mutant rhino after you. The Na'vi is aware that everything is about maintaining balance, therefore, a perfect natural ecosystem in order to thrive.

i think the one who kena own doomsday weapon are the humans.. so that's why their on Pandora to blast out the mineral thingie.... probably to make better weapons.

i think its fun to temporarily indulge myself in these kind of stuff once in awhile.

Like discussing how can Superman manage to catch Lois Lane as she plunges down at 50 miles an hour with his bare hands, decelerating just in time 2 inches above the ground while she miraculously did not suffer massive internal pulverizing from his arms of steel.

Imagination + logic... we do that a lot as kids