The fan shroud for this case is relatively easy to modify, actually. The aluminum is thin, and easy to cut and bend. You can mend any induced "rifts" with aluminum flashing tape. The biggest difficulty with this mod is that the rivets used to join the plates making up the shroud will loosen if you tweak them too much. I modded my xb01 shroud so much that it eventually fell apart at the rivets, and I wound up making a new shroud from aluminum sheet I had on hand. Just take your time, think about what it is you are trying to achieve with any such mod, measure thrice, cut and/or bend once.
In answer to your original question, with enough air flow, I think it's reasonable to assume that you could run without the shroud at all. The shroud is designed to train the airflow from one fairly sedate Lian Li fan over your components. If you are running two or more fans in your Lian Li case, you should have air flow to spare. You might consider adding sinks to your RAM, the "southbridge" and the HANA (video compositing) chip.
I wrote a rather lengthy post, some time ago, in this forum about the modding of PC heatsinks to fit 360 CPU and GPU. Look it up if you are interested (search for "Shin Etsu" using the search feature for this forum, the post in question is appropriately named and showed up on page 2 when I searched for it).
Edited by strapmonkey, 21 June 2012 - 02:04 AM.