As to your first post. The entries you pointed out direct the game to .ITEM files.

Code:
item           tree_A_palm
means
Code:
data/items/tree_A_palm.ITEM
.ITEM files are used in settlement plans. Every building is loaded from a .ITEM file.

The .CAS files that it points to arent actually .CAS files. They are .BPI files which are similar to .CAS files but the game uses them to create the physical data about an object so that troops cant walk through it and the camera gets bumped up by it. You can find those .BPI files in "data/models_building/INFO/" but they won't do any good.

What I actually did for our palm thing was open up these .ITEM files and resave the models in .CAS format.


As to your second post I can only make a guess as to what may be happening because i dont know enough about vegetation. Did you specify a layout texture for the entry to use? If not then it will come up empty.