Another thing I noticed, which actually happens with static objects in Forge in Halo 3, is that after you remove a static block from under a non-static object after the object has settled, the non-static will stay floating, unless disturbed.
I found another interesting thing to do:
Select a static kind of block, and then hold down left click while holding left or right arrow.
Creates funny rainbow circles.
I like the changes, but it does get annoying having to use the mouse to move the screen around, perhaps let us use the arrows to move the camera and use Spacebar + Mouse Wheel to rotate objects? Just a suggestion.