Currently it is a pain to select mobs that are partially occluded by scenery - there's this BRIGHT health bar right in my face, but clicking it fails quite frequently if some non-interactive scenery is overlapping it.
I have to fiddle around trying to find the clickable part in the heat of the battle, move the camera - and finally take my eyes off the centre of the screen and resort to clicking through the targets I have enmity on, on the side of the screen.

Essentially, it would be quite nice if non-interactive parts of the scenery are just "clicked-through" - in particular in favour for those bright health bars.