Overbore, don't worry we haven't given up on you yet ;)
As I said, I'm no expert on RT stuff, but the concensius, from my understanding, is that most seem to keep the midvalve in tact for MX application, and use the check valve (RT system) for woods use. This is not carved in stone or anything, and I'm sure there are lots of variations out there that work fine. I also wouldn't worry about the GV being "out of date", as I'm sure they will work far better than your present setup and give you a great opportunity to learn how things work and tune yourself ...kind of the "teach a man to fish" deal. Sure, offshore trawling is more modern, but somehow just isn't the same :)
As far are the fluid movement in rebound, there is a rebound portion of the basevalve in most forks. The fluid is moved through this and also through the damper rod. In fact fluid flows both ways through the damper rod (comp and reb).
Removing the midvalve shims (repaced with checkplate) will effectively make the fork softer, particularly at midstroke...or at least that's my understanding, as I've never removed one myself. I know from tuning them, that it seems to effect this portion of the travel and the "feel" when entering turns. Stiffer gives more feedback, but can also result in a harsh feeling at the bars.
This is why I think alot or woods guys like the checkplate better as it's an easy and quick way to get response on the roots and rocks they deal with daily.