Oh My God/Goddess

[kewnya txamew'itan]

It's clear who Cameron is trying to portray as the good side but it would equally be possible to portray the RDA as being in the right and the na'vi as just being a bunch of Luddites. As I said, shades of grey, not necessarily identical ones (this reworked avatar would be a harder way to do it), but, in my opinion, the situation itself is much more even than most people interpret it as being (likely due to ever-present confirmation bias).

[omängum fra'uti]

This is turning into a cultural discussion more than a language discussion, so moved it over here.  Carry on.

[Human No More]

I'm not sure if the Na'vi are superstitious in that way, as they have direct contact with Eywa and probably DO at least partly understand the nature of her, meaning they also know not only limitations but also that she doesn't actively intervene, so it wouldn't occur to them.
There is definitely some confirmation bias in interpreting things like this, but the truth is, we see a lot of the Na'vi and nothing of such behaviours.