It seems that material billboards disappear when their center point isn’t on the screen anymore. I want them to be visible as long as the whole thing is still on the screen, not only the center. Is that possible?
You need to adjust the boundings. I am not totally sure what you are trying to do, because I only know this problem concerning particle effects.
Is there a way of setting the bounds without C++?
Maybe post a few picture what the problem really is at the moment, I am not sure if I think of the same.
Nevermind, the problem seems to have magically disappeared when I opened the editor today 
Maybe I had it in some kind of a buggy state where the bounds weren’t calculated correctly…