Just to add that we did it. It stayed up fine with 2" wooden stakes for the outer and EMT conduit (1/2") for the remaining poles. Used barrier fencing at 6' high. Poles stayed in fine, no problems once it was up. So if anyone's reading this in the future and wondering if it's possible the way we did it, it is and was. Watched various people charge through it without damage, although being deep playa might have helped.
If you found & tried it, thanks!
Already thinking of how to outdo it for another year, now we know what the playa/elements are like. Am thinking of a multi-level maze that's a lot harder & more "arty".