I made a serious mistake by turning the crankshaft counterclockwise when installing a new cam timing belt. Now the engine will not rotate more than 90* clockwise without a mechanical impediment. Would this be the balance shaft system attached under the crank itself? Help! Thanks, Cordially, Richard Cannell

 

You should be able to rotate the engine by hand CW without issues. The balance shaft system is geared to the crank and can't get out of sequence.

The engine should be non-interference thus it should not matter where the camshaft rotation is. However if there is mechanical impediment best to check this out as you are doing.

Is the timing cover still off?

Rotate the crank by hand whatever direction you can to obtain 0 degrees at the harmonic balancer. Then look at the cam pulley and see where the pulley spoke with hole is. It should either be aligned with the mark on the cam bearing mount or 180 degrees off. If some other location there is problem.

To resolve this issue remove the belt and rotate cam (if possible) to align the pulley. If you need to also rotate the crank to prevent binding, do so.

As long as you don't force rotation or worse yet use the starter, no damage will occur in trying to realign the pulleys.

And look around in case something else is hitting, there is not a stuck valve, etc as the engine is non-interference.

 

Did you try starting the engine? If so the valve may bend and shot pistons that would surely lead to a seized engine.