Jason,
I haven't played Wild Horse. Many whose opinions I trust think it is very good, but put it a notch or two below Rustic, just as you put Rustic a bit below Wild Horse. Would it be reasonable for them to insist that you are "dramatically overrating" Wild Horse because you think it a bit better than Rustic?
Regarding environmental areas, I agree with you that they are the functional equivalent to water hazards. When Rustic first opened there weren't nearly as many, but after the big fire they had trouble with traffic (especially carts) entering the burn areas to find balls, so they greatly expanded the areas marked as protected. At the time I thought it was supposed to be temporary, but unfortunately it seems to have stuck. I don't really like excessive water or water equivalents on a golf course, so ideally I'd prefer fewer restricted areas at Rustic. Practically, though, except on Nos. 6 and Nos. 14 from the back tees, the areas aren't really that big an issue.
As for your comparison with Doral, it strikes me as completely ridiculous. You are dramatically overstating the lost ball potential at Rustic, especially if your 15 handicapper is playing the recommended white tees (6050 yards.) Most the fairways are at 60+ yards wide with the corridors 80+ yards wide. There are a restricted areas somewhat near a few greens but, unlike at Doral, there are no places where a ball can trickle off of a green and into a the hazard, and there are few instances where a golfer must flirt with the hazard to safely reach the green. As at most courses, there are definitely a places where one can lose a ball, but even in howling winds lost balls are rarely a major issue.
As for the "first time player" who doesn't know where he is going or which native areas to avoid, I'm not sure that ought to be the standard. Regardless, I'd strongly recommend that the he try to avoid all of the native areas. Given the 60-80 yards of width, that doesn't seem to be too daunting a task.
In short, the Doral comparison seems so out of line with reality that I understand why another poster questioned whether you were familiar with the course. There are few courses in the region where lost balls are less of an issue, especially when the wind blows.