Before you put them together, take out your current scorpion and rearrange the habitat. Then put them in at the same time (this helps remove established territories).

Anywho, while little is known about diskinetic syndrome, I'm guessing it's a neural degenerative disorder (based on symptoms of spasming and such) -- so I doubt it's contagious.

Keep in mind the above is nothing more than an educated guess.

Edit: Apparently in humans it's a form of cerebral palsy, so not contagious -- but it's not necessarily the same disease in inverts just because it has the same symptoms.

Also found this link: http://www.justanswer.com/questions/1ky94-dyskinetic-syndrome-tarantulas

(Sorry if this post was utterly useless, but I don't think there's any solid research on this phenomenon because there's no economical motivation for anyone to research it.)

I got it. Thanks Mr. Mordax

Definitely poop on the tail.

With the new substrate and higher humidity, he seems much happier. He moved the tree bark hide around to the point it's almost flat against the substrate and burrowed in, haven't seen much of him since so I'm guessing he's doing okay. Can anyone tell by the pictures if he's sub-adult or adult ?

Definately an adult. You can tell by telson colour;
1) juvenile = white
2) sub - adult = yellow/cream
3) adult = brown/red