Here's what I spotted.
At :37, the guy with the sliver face reminds me of characters from Captain Eo.
At :52, there's your smooth criminal lol
At 1:08, dude has a white spangly glove, and a tux with sleeves rolled up, goes up on toes
At 2:25, another dude has a white glove
I wonder if there's a significance to the martial arts class learning MJ moves...
At 2:35, big guy in white suit also has one white glove, and almost does a crotch grab lol
At 2:37, guy in black fedora, white socks and loafers doing MJ moves (I guess the guy you refer to, IvoryKeys?)
At 3:04, guy does a Bad-type move with fingers, wearing black fedora
At 3:23, sumo wrestler does Thriller dance move lol
And the Dirty Diana stuff, like you said IvoryKeys