a- reclaimability... all features are 100% reclaimable, regardless of the tags that are set... that needs fixing...
b- transparencies... missing? maybe use a specific color, say, cyan, as a full 100% transparent color, or use the alpha channel, but as I understand the alpha is for teamcolors... but features don't use teams... make it an exception??
c- this is a loooong shot, but the collision detection, needs rewworking, vertical "collums" of the "footprint" for collision detection, just isn't working for the larger features... say mesh collision detection? it wouldn't take much to generate simple mesh objects ~30 faces of not less for almost every object, and generate a "semi-accurate" collision detection..
d- the ability to walk, drive, build, and do whatever, ON TOP of features... (I.E.) so I can make bridges! this would require a mesh collision detection however..

e- the fov for the draw on the larger features needs to be increased... say linerally with footprint size... as when you make something REALLY big, and turn the screen, it will disappear from sight, before its off the screen...
(I also understand that changing this will have a LARGE impact on FPS and quite possibly, may not even be possible...)
those are just my observations as of now, if I find more, I'll add them to the list....
-Lathan