I know goldfish show preference for some color substrates over others. I Imagine those occassional bubbler things would bother a lot of fish, but i also imagine that most of them would get used to it over time. as far as the 'unnaturalness' of it, i agree with others who have said that if their needs for hiding, exploring, establishing territory etc are met, they dont much care how tacky the objects are that do it. I couldnt stand to not have at least Some live plant in there. maybe a java fern , they look kinda fake lol.
It just feels too unnatural to me without it. Not looks wise, I mean for the fish/water quaklity somehow.
Too bad about the black light. they have some really trippy decrations espesially for under black light. (the would tempt ghostshrimp to soak funny mushrooms in the tank)
fish often freak out with a sudden change of light. maybe thats all that happenned to Ham Hams friend?