The expansions and main bases including mineral lines are not able to be hit by siege tank fire (Unlike The Hunters), unless the tanks are right outside your main choke.
Black squares on the minimap preview are just the new ramps not supported by nibbets software.
Minerals at a few of the expos are stacked 5x for space reasons.Natural expo minerals are 5x2500.Middle expansions mineral patches are also greater than 1500.