A feature to suppress the top levels of the taxonomy (and all the child taxonomy areas from that top level area) is underway and should be available soon! Thanks for the suggestion!
What would really be helpful would be fuller customization; ability to move terms between levels, etc. For my example below, we obviously wouldn't want to suppress to top level under which Library and Information Science falls. What we would like to do is move Library and Information Science TO the top level.
This would be extremely valuable to us, as we have several professional graduate programs, one being a library and information science school (it's very difficult to guess what subject library science falls under!). And I would guess that the grad students would be the most heavy users of the product.
Allowing customization of this message would be ideal.