I'm not an expert on Scenic, but I am in the area, and have flown the canyon commercially, so, since no one else is responding, here's my .02.
Plan on living in Vegas or the Canyon if you want to fly tours. In fact, it helps if you already live here. You'll get home every night, and work mainly during daylight hours, but many canyon flyers work 5 days a week plus one day on call (one "solid" day off, which can be subject to debate depending on the company). I really don't see it being "commutable."
I've got a buddy who recently went through training at Scenic, he say's they're still 121, 600TT is the mins (although they have occasionally dropped to 500TT) and starting position is right seat in the otter at $14.50/hr. Neither of us have seen a Scenic 402 in operation, so I don't know what to tell ya about that.
If you see a 402 over the west side of the canyon, it's probably King Airelines.