Dont realy understand what you mean grayed out.
IN Wrpedit if you want to add a object , just double click (leftmouse) on your map ,
you then should get a dialog panel"insert new object" press the browse button . scroll down to Data3d folder click that, then you should get a list of ojects "p3d" extension. highlit seomthing that will work like ammostore2.p3d . it will just highlite, dont worry just select ok button . you will then be back at the dialog "insert new object"
make sure fit to ground is checked. select ok. you should now see a grey box on your map . if you want to see it slect camera tab under the objects tab . select "set by mouse" click on map once . now hit f9 . you should see the ammostore2 building .
watch out zooming to close in preview .
probably not what you wanted to know. but hope it helps.
if you want to select a object so it shows in selected list hold shift key , while you drag and hold(left) mouse you shold get a green box. and it will be listed in selected object list . with that you candelete, which is smae as crtldel but has a warning first.
below that is a list of object you have loaded. there you can right click and remove unsued or duplicates.
thats about all i know. as far as objects.
Happy island maken!
OH wrpedit public beta 0.93