On question #1, the center star cam does not need to be removed. But, it does have one arm longer than the other three. That longest arm needs to trigger the hour chime, which is why it must be synced with the minute hand. The longest star arm is the only one long enough to release the chime correction.
For #2, since only the longest star arm can release the chime correction, they need to work together at the hour mark. So the chime correction must match the longest star arm as well.
For #3, when the longest star arm is ready to trip the hour, the locking plate must be sitting in the 3/4 position. Then, when the minute hand reaches the hour, the longest star arm will lift the lifter high enough to release the chime correction in order to play the 4/4 chime and then initiate the strike.
If the chime correction happens at incorrect times, it will lock the chimes and won't release them until the longest star arm lifts it free.
As this is your first chimer, I understand how confusing it is. It was not your responses, but that I could not find in the sequence of posts if you had followed the proper order for setting up a chimer.