Toggle on/off individual UI elements
So many souls, so little time. ~ Kraag Deadsoul
You raise an interesting element and yes, I agree that this would make the interface much more dynamic. I also wish to propose a modification and that would be to allow the concealment of the users avatar (character) and the turning off of the UI (so both are off at the same time) so that it is possible to take video and make still images of the truly amazing landscape and characters in Guild Wars 2 without your character being the relative center of every image. At the moment I get around this little problem by placing my character as close to a surface (a wall, tree, etc.) as possible and then sitting down. Most of the time this acts to conceal your character and allow the taking of an image.