Ok, I've just now made my 7th trackball misclick/misdrag in the Tactics Trainer in the past two days.  Is there any possibility of an option to use two-click movements with the chess.com interface?  I'd be very appreciative of this.  Thanks!

two click is possible... i've been using it from time to time now... try it.

that should already be in place :) click-click should work. if it doesn't, what browser are you using?

Throw that trackball in the garbage, and use a mouse like a normal person would :)

trackball is better for you ergonomically.

i actually know a guy who uses a trackball, but with his foot under his desk, so he can do keyboard and mouse at the same time! 

Well, call me stupid.  It does work already.  Thank you and I apologize for missing this.