This thread is very helpful and I want to bump it up a bit. I had a similar question. I had only "dabbled" in reverse breathing, but have been practicing and learning Qigong for some time.
I find this system to be the best for me at this point in my life and for the foreseeable future and hope to someday learn with Chunyi Lin in person.
For now, I was having problems with the complications of:
A) learning the movements
B) coordinating the movements with breathing
C) Learning Reverse Breathing
D) Slowing down the breathing
E) Other stuff 
From what I am understanding Shawn to be saying here, and based on Chunyi Lin's development of his system (and BTW, all of the good teachers I have had, always were learning and improving what they were doing and teaching. For me, that is a sign of true progress in the Tao), it is okay to just work on learning the movements at first, and not bother too much with the breathing at all.
Then, once one has the movements down to some degree , then one still should work on the flow and the slowness and kind of forget about the breath,
Then, when one has developed flow and slowness (similar to how I learned Tai Chi Chuan), then one can work on reverse breathing.
I find reverse breathing very difficult for now (at least while trying to learn the movements and forms), but am totally convinced that it is well worth learning.
Shawn's response based on Lin Sufu's teaching helps a lot to break down the learning steps into bite size pieces in a more relaxed way.
I was kind of intuitively thinking that this sort of approach would make more sense, at least for me before I read this thread. It is nice to know that I am "tuning in". 
Thanks to Shawn and to all those posting here and to Curious1 for starting the thread. This is a keeper (bookmarking it now) !
[This message has been edited by shakurav (edited April 03, 2006).]
