To me it doesn't appear to have unbonded, it looks as if it is 1 continuous threaded piece which is moving along threads inside the hub. When it moves, it moves evenly and smoothly, there's no side to side movement or anything like that
Looks like meant to be like that, you have cut outs on lockring thread to tighten the hub in the flange, tighten that and then try to unscrew the cog. Or use the cutouts to unscrew cog. Lockring tool or similar would be advised.
Nope.
Entirely supposition on my part, but I'd think they are to prevent the hub turning and unbonding from the disc when you remove the sprocket.
It looks like the hub is in two parts secured by the screws, so you should be able to completely disassemble and re-bond the disc to the flanges.
But...
