I don't know alot about the CNS but I'm under the impression that you cannot condition your CNS as your stating, maybe you can, I'd have to ask someone. I really don't know a thing about that....that's a very complex issue when you think about it bacause now, I think your getting into the whole endocrine system and how it would react, I might be totally off base but I think the endocrine system has alot to do with the eventual condition of the cns...I'm not a doctor.
the pump thing is tricky, depends who you talk to, like I said if I do jumping jacks for an hour I'm gonna get a pump but I don't think the overload is enough to induce growth, I could be wrong but this is what I believe. Personally I don't put any credence into it, if I deadlift 700lbs for 3 reps I ain't gonna get much of a pump but I'll probably gain in the strength, muscle dept. It's apples and oranges.
Anyway if you think it works go for it, your a big dude for being as tall as you are...the only way to really tell would be for you to get a LBM reading, train and eat like you do for a month get another LBM and then train heavy but short with the same diet and get an LBM again to see what induced more growth...might be more trouble than it's worth.