Matt, if the key is broken, the CAS can go back in any position, but there is only one position where the engine will even start.
Idle is basically controlled with fuel. Variations in timing at idle are likely caused by the map being moved to a different load/rpm cell. Timing doesn't vary by more than 1 degree at idle, in my experience.
Callan, WTF? You don't need bolts shoved up coil packs. You peel back the small rubber cap on the "dizzy" end of the plug lead (maybe even cut it off) and the lead becomes the spark plug for the coil. The other end of the lead slips onto the spark plug (as it would in a "dizzied" application). Then connect the timing light to the spark plug lead (note the pickup is directional).