You are correct about everything except the desired timing number of degrees. The "auto advance" ignition units are actually auto retard. You set them at 28 degrees. The timing retards for starting and idling, and then advances, achieving the actual 28 degrees you set it at when the engine hits around 3 to 4 thousand rpms on most units. At super slow rpms, such as when slowly turning the engine over by hand, the timing is advanced so that you can set the desired total advance. When the engine is cranked to start, and/or idling, the timing is retarded.

AV8TOR