Apparently workers can pick up sprites, according to payne at least... Is this true, and how does one do it?

I think he means Powerups.

preplaced unit sprites act almost exactly like their unit counterpart. unit sprite powerups are the same. When disabled, they can't be picked up and have no collision box.

Almost any sprite can be "moved" with a worker via the hallucinated powerup glitch. It's pretty useless, though, since it won't pick anything up, just make a new sprite.

He was talking about the pieces of terran mech units, (turrets).