keep it simple stupid.(KISS) That is one of Stinkbuds favorite sayings. This system is designed the best way for using an aero/nft style hydro system, imho. It is a well thought out system that works amazingly well with zero alterations. Ya don't have to re-invent the wheel. Having the pvc manifold with the sprayers attached in the fence post will work much better than with tubes. I'd be afraid that those lines will be a drag when you disassemble for cleaning, or possibly clog. It just seems to complicate an already simple system. The PVC manifold keeps ridgid so roots aren't a problem. The only change I would make is the extra ball cocks to expedite changeovers. Try one with the simplicity that Stinkbud designed it, before you go and get all that fancy shit. I've run these systems since 2009, and with the 4" fence posts too. I never had an issue with the roots plugging ever.
Once the roots pack it in, it becomes an NFT system. There is no more aero. It's much more of an nft system than an aero system by far to begin with, but it works very well. The Stinkbud Aerovegger is true pure aero, and growth rates are amazingly fast. Hence the 250 watt metal halide instead of 400, or larger. It would grow too fast. These systems are designed for a perpetual garden cycle. There's a 3 week turn around. 3 weeks growing roots in the aerocloner, 3 weeks with the aerovegger, and once you get 3 of the aero/nft sytems going, with 9 week strains. You harvest a rack every 3 weeks, and replace that rack with plants from the aerovegger. At least a lb every 3 weeks. More like 2lbs though from my experience with a 1k for each 6, or 8 plant rack.