Glad to hear you've gotten the lighting issues almost sorted out!
If it was your beardies first time outside, then it's perfectly normal for them to just kind of freeze out of fear... It will take him some time to get comfortable out in the open like that, best thing you can do is stick close to him for comfort, and reassurance. Black bearding you could have just been from being startled. if you approaced from above he may not have seen you coming until the last min, try to approach from the front, and move slowly for the first little bit while he is getting used to being outside.
As for the stopping... I dunno, these little guys are packed full of strange little things that they do, I wouldn't really say anything sounds wrong with anything that he is doing tho'
I'd like to add that our two beardies, Fred and Ethel, brother and sister, 12 months old, they love thier romane lettuce daily, one or two leaves chopped up, and fresh apple cut into small 1/2 inch cubes, about two or three heaping tablespoons. We give them at least 5 to ten live crickets daily, and once a week we give them a dozen each of giant meal worms.
They do not like to eat early in the day, it takes them an hour or two to wake up and get warm and moving again. They get VERY active when chasing the crickets, and they get very active when let out on the floor. They often sit in our laps or on our chest for an hour in the evenings, then suddenly, they burst into activity and want to run across the floor.
And I swear, it seems that they love to watch TV too. They are a joy to us, sort of like kids.
Still waiting on the repti-sun, haven't yet ordered it, will have to get round to it.
Rocky is becoming more and more active and has been head bobbing at his reflection in his window. Hungry for locusts ever more, he's getting around 50 a week. Is also eating lettuce occasionally. My sister will be looking after him in July as I am going away for holidays. He's getting regular baths and after each one decides to run around his tank before settling in a nice spot and snoozing for the rest of the day
Doing well so far, will let you know when something happens.