In the Endor tree ODF files, I saw this command that looks like SwingSpeed = "1"
I am assuming this what makes trees look like the wind is making them go side to side. I attempted to add that command on some Mos Eisley stuff like the pillars and evaporators but it didn't do anything. Both the trees and Mos Eisley objects are class label prop so I don't understand why it isn't working.

This isn't important to solve but it would be nice to know how to set up for other things in the future

Interesting, at first I wondered if that controlled attached treeclump odfs, but the endor trees don't have them. I opened one in xsi and noticed that the foliage is separate from, and a child of, the trunk, so maybe swing speed looks for a child mesh and moves it around a little.