Ra's use of the word 'ego'

[zenmaster]

The interesting thing is that you might find that the you observing the ego isn't the ego anymore, though if you try to pay attention to that it switches back.

The "ego" is developmental and at some point, even in context of 3D awareness, many of those negative qualities cited simply do not apply anymore. So it's a catch-all for negativity. I think we might be able to thank Alan Watts for the confusion.
As far as ego meaning "I AM", that's a little bit of a stretch simply due to the fact that the original meaning was simply 'I'.