horlback designed a system that had no airstones...the circulation, if done correctly
does not require airpumps, as the recirculating water provides enough oxy for your plants, for instance: ...in nft there are maybe an airstone in the res and that's it,
...in aero sprinklers spray create oxy, no airstones, except res...

With that said...It will not hurt a thing if you use airstones in all your buckets, but with airstones in the main res, you do not have to put them in your buckets...I would though, if it is within your budget, because, once again, it doesn't hurt...

As far as airstones damaging your roots...not gonna happen...
As far as fast flowing water, you can do that also, as long as you have your runoff,
set correctly, the more flow, the more oxy...some people use powerheads!!! Just make sure that you don't blow the nutes out of the system...hope this helps...
...sorry about the chapter...