So, as a recap ... what do you think the main issue(s) was/were?
IW
IW - I've been asking myself this same question many times over the last few weeks. Taking a scientific approach would be to change one thing at a time and see the result. But once you've got those cases apart you need to fix every possible contributing factor before you button them back up.
My guess would be the major issue was the remaining glass beads in the system making their way to the crank bearings. And I theorize that the over indulgence of assembly lube didn't let them flush through with the oil. It's amazing how just a little bit of grit in those bearings makes it extremely difficult to rotate the crankshaft.
I'm waiting for a new front brake piston to arrive, but once I've got a way of stopping, I'll be taking it out for a spin. Then I'll do proper timing, and after that I'll do a complete oil change.