Somebody was asleep at the wheel, in the sense that he moved an arsenal into that room, in just one day, and did it under folks noses. On the other hand, if you see the same guy bringing in 10 different suitcases (don't know the actual number) do you get alarmed? And if he moved stuff in over the course of an evening, night and morning, then would any single security guy catch anything amiss? I don't know.
Didn't see the Adams video, so no comment. The money transfer? A guy taking care of his gal seems to be a description that fits the act. Her willingess to return seems to indicate she had no prior knowledge.
Twice before he checked into Vegas digs adjacent to outdorr music festivals. It is easy to wonder if he was waiting for just the right one, I have no problem there. those may have been dry runs, which lends itself to the intimacy and detail in his planning. It would be interesting to see the surveillance tapes from those motels for those dates.