Probably the extra thrust movement wasn't the cause of the broken piece from the pulley, but it is definitely not right. I'd say most likely is the thrust ring on the intermediate shaft has broken off. Really easy to check. Remove the pulley and remove the two bolts that hold on the seal carrier.
Hey, was the belt riding off the end of the I-shaft pully?Off center?
I only skimmed that thread. It sounds like the difficulty in turning and the breaking of the thrust ring on the int shaft could be from the same issue. My recommendation is the same as before. Pull the vac pump and make sure it spins easily. Put a socket on the oil pump shaft (careful not to drop it in the sump) and spin the oil pump to make sure it spins easily.
Libby is suggesting pulling the two parts that are driven by the IS itself. The gear on the back spins the oil pump which is two gears that squeeze it up and out to the rest of the engine. The Vac pump may also be a gear driven device if you have the upgraded on. But it's shaft fits on top of the oil pump and if either is jammed up for some reason the IS will not turn freely.Taking them out one at a time and testing is done easily If you remove the timing belt spinning the oil pump should show up as a turning IS shaft so be aware of that. The vacuum pump can be turned by hand once it is out of the engine. Good luck on this.