First, make sure the wheels and rollers are clean.
The clicking, jumpiness and high current draw all point to a mechanical problem in the drive train. I would first inspect all drivers and rods for bent components and then take off the boiler to check for binding on the motor, flywheel and drive train. Turn the motor by hand to feel any resistance. After that, try powering the loco upside down in a cradle directly from a transformer (conventional) to look for problems. Continuing to run it while it draws excessive current risks burning out traces or board components. I bought mine used with a dead board that had burned out components and traces. Because of this problem, Weaver issued revised instructions for modifying the board connections to bypass some of the small traces.