Laying under the beam seems a bit dangerous. I don't think it's ever a good idea to put yourself or a gymnast (whether they're under or on the beam) in a position where someone could potentially be hurt. Having people lay under the beam during a kid's routine wouldn't help any if she broke her ankle during a fall and couldn't compete anyway. (I apologize if I misunderstood you and you're not actually having people lay under the beam while a gymnast is on it.)
Other than having kids lay under the beam, everything else you described sounds exactly like what I tried to do with my kids the first year I coached competitive team. However, since then I have focused more on actually teaching the kids how to focus rather than on trying to distract them. Throughout the year, I will bring the team together and we will discuss what they need to be thinking about during their beam routine, what it means to focus, to concentrate.
I talk to them about focusing only on what they are doing, thinking only one step ahead, about what they are getting ready to do. That means 'forgetting' falls as soon as they happen, forgetting that people are watching you, forgetting that you could have done that skill better. Only think about whatever it is that you are about to do. So if you've just finished your leap, you are thinking about your kick, handstand.
Don't think about anything you've done before, only what's coming next. If you fell on your mount, obsessing over it throughout the routine will only make you wobble or fall more. Don't think about anything outside of the skill you are getting ready to do. Nothing. Nothing before, nothing after. Nothing outside of you, the beam and the skill you are about to do. That means no thinking about people watching you, no thinking about the judges, no worrying about falls, etc.
In addition to that, there are many psychologists (sports and otherwise) who have chimed in on positive vs. negative thinking. Thinking "I'm going to fall on my handstand!" will probably cause you to fall on your handstand, because you are thinking about falling. Thinking "Don't fall on the handstand!" may seem better, but it's really not. Again, what are you thinking about when you think that? Falling! Sure, you're thinking that you don't want to fall, but you are still thinking about falling. The mental image you create when you say "Don't fall!" is one of you falling! "Stay on the beam!" is a little bit better, but only marginally, because you're still thinking about the alternative (falling).
Good thinking is thinking about your corrections, what you need to do in order to do your best handstand. So as you're getting ready to do it, your thoughts should be something like, "T in, squeeze, hips square, finish!" Thinking about the skill you're about to do and your corrections (the corrections that your coach has given you) will help you to focus on the skill and not become distracted, not wobble as much and therefore not fall as often.
One other thing I tell them is to look at each meet as practice for the next, bigger meet. Each regular meet is practice for sectionals. Sectionals is practice for Level 4 states, which is practice for Level 5/6 states, which is practice for Level 8 regionals, Level 9 Eastern Nationals, Level 10 nationals, Elite Nationals, Worlds, the Olympics, which will then be practice for their second Olympics, etc. At each meet, they are to practice their focusing skills, they are to practice competing well under pressure. I tell them, if they can master these skills now, they will kick butt at level 10. We all know of talented level 10 and Elite gymnasts who never did as well as they could have because they don't compete well (Vanessa Atler
). Now, I know level 10 and especially the Olympics is an unrealistic goal for most gymnasts, BUT getting them to think about focusing and competing as skills that need to be perfected, just like a handstand or a cartwheel, is the key.
Again, we talk about these things often, throughout the year, especially during the competitive season. I treat each meet as "practice" not, "OMG it's a big scary meet!" One thing I do continue to do is having them perform their routines individually with teammates watching. I don't do that too often, especially if I have a larger group, but it needs to be done some, especially in the first year of competition.
Even though you just have a week before states, it's not too late to talk to them about some of these things, especially about what they should be thinking about during their routine (next skill - corrections). Good luck!