Hello Rick,
Lately i have become interested in the various projections of the world onto a flat map. There is a typo in your info above; Latitude lines are parallel with the equator and longitude lines run North and south. Interestingly enough, longitude lines on a globe are not parallel since they all meet at the top and bottom. I don't know how this is compensated for on a flat chart. Although we are not allowed to travel to the north or south pole, so the lines coming together at top and bottom is not really relevant to us.
Thanks for the reminder that the magnetic field curves and a compass only gives a rough idea of true north.