You may be on to something there about the timing screws Scott.
I’m not sure whether they are always gold or platinum on 992s. Randy’s pretty up on Hamilton so maybe he’ll see this and can let us know. The screws will usually look different than the other screws on the rim. The screw is usually longer and the fit is tight yet smooth to allow for easy adjustment and to stay in place after the adjustment has been made. This is unlike the other screws which are often loose and sloppy if not snug against the rim or washer.
As far as the safety roller goes I would think that there would be some loss of motion to the balance if dragging on something or if it is in someway being interfered with by the guard finger. Maybe not though. Also if something is keeping the safety roller from moving up against it’s locating shoulder or part of it is sitting a little too low due to the crack it could be contacting the balance jewel setting. I don’t think this is the case though as it would probably be running slower in the dial up position rather than pendant up..which is the opposite of what’s occurring. If this is a two piece double roller and you would like even more to do this weekend you could always remove the safety roller and do a test without it to see what happens. 
Enjoy,
Bob
ps…if possible please post the serial number (or a pic).
Thanks