I don't know much about the mechanics behind neutral coasting, or the Astro/Safari transmission. I do know they are built with certain tolerances and the shifter is simply an electronic selector for the gear you want selected, no hard mechanics, and ihatemybike, aka Aaron, would not advocate something that is detrimental the the vehicle.
It's actually incredibly easy to do and doesn't take much thinking or effort. I picked it up very quickly in just a few hours of driving. You see a steep hill coming up (steep grade signs are like Christmas to me) and pop the vehicle into neutral with a simple push down on the shifter, when the grade levels out and you start to slow, pop it into drive with a simple push up on the shifter, and re-apply pressure to the pedal. Neutral and drive and right next to each other so a simple push up and down is all it takes.
Same formula for stop signs and stop lights. Looking ahead and seeing a stop sign or stop light, sometimes up to 1/8 mi I pop the van into neutral and coast to a stop, re-apply pressure after shifting back into drive and you're good.
If you think about it, it really is worth it and adds up considering how easy it is.
As for brakes, unless you're on a really steep grade and gaining a lot of speed you don't need brakes, if you do need brakes for a long period of time use 3rd or 2nd gear and use your engine to slow.