I go to school at wyotech. I am in a class at the moment that has all the stuff for pretty much anything.
They teach that cutting is ok. Honda racers...they get adjustable coil over sleeves. Not cut their springs. They aren't that bright.
Several of my teachers are Ex-race car drivers/builders, and they ALL cut springs to lower their race cars. Cutting the springs increases the spring rate, which is what most lowering springs are made for, to get an increased spring rate for less body roll. And for the complication, its not so bad. Last thursday we cut the springs on my friends WRX, and it drives awesome. Just make sure your measurements are right.
And BeemerWorld, what is the moleculer structure that you're making referance to?
And for the fabrication of my own sway bar, I wouldn't use a "pipe" bender, I'd use a tubing bender. I Also have an oxy-acetalene torch with heating tips(Which I wouldn't use, because heating of suspension components is bad. It makes them brittle(and the last thing you want is a brittle sway bar)). I've researched this stuff, its not really that hard. And I don't think BMW gets some magic moon metal to make their stabilizer bar, So I think the 4130 Steel Tubing I would be using, would be fine.
I'm not gonna sit here and post "posts" about stuff I don't know anything about.
Buying stuff is nice yeah, but if you got the means to make your own, and make it just as well, then why not save the 4-500 dollars you'd spend on the other stuff? It makes sense doesn't it?
Oh yeah, and for one more referance about spring cutting, check out Chapter 5 of Herb Adams book "Chassis Engineering". Specifically page 35. I'm sure that guy knows what he's talking about.