Wow, yea, I am not on the same page as most folks. At a low pay job where customer safety is not a concern, I could care less if a staffer uses their cell phones a little while between customers. In fact, I am happy for what few little perks they have in an otherwise thankless job. Having a smart watch that makes using the phone/text less obvious is even better. The only caveat is when a customer is actually needing their help. So, yes, in your scenario the employee should have spotted you and wrapped it up in 15 seconds or less. It takes, what 5 seconds to say "Gatta go, need me to call you back?". ...and then be super nice to the customer that kindly waited the extra 5 seconds.
I'm happy for you use your phone unobnoxiously.
I can guarantee you, at the rate Disney would pay me, If I was not with a customer I would answer calls from my kids without thinking twice. If they wanted to fire me because I took 120 seconds away from stocking shelves to see what my kids want, it would be their loss.
I have a large staff that report to me. I would never tell my staff they could not take short phone calls between customers. They work so hard and are much too valuable to me to be that bloody petty. Just thinking about it makes me lol.
And to tell them they could not wear a smart watch is absurd.
Sure, there are lines you can cross with personal stuff at work, but 5-15 minutes a day on phone or text is not one of them.
As for the yawning, that is even tougher to prohibit. A gentle coaching if it is ridiculous in frequency, but other than that, I think don't worry about it.
I am in full agreement however, on rides or attractions that are sub par due to malfunctions. It should not be that difficult to keep it professional on a grand scale.