My glider, Hamlet, does not have as high a level of anxiety as some of the gliders I've read here, but before he was neutered, he was really bad. He has done the whole "running in circles around the top of the cage for hours" thing. He got much better after I got him a cagemate, Rafiki. She sometimes does that, but she has her own issues (she was abused, I adopted her from a rescue.)
Sometimes little things freak him out, but mostly he gets stressed from fights with Rafiki, or if the dogs get too close. Which is his own fault. He likes to climb down to their nose-level and taunt them, then he gets upset when they finally lunge at the cage! (We've mostly been able to catch and correct this behavior from the dogs.)
Cleaning the cage doesn't bother him in the least, but he doesn't like to have his
toys changed very often, or he won't play with them at all.
That's wonderful! So glad to hear he's doing well!!! 
