Jim,

A1. The regulation distance was 14 yards between pieces (and the piece was 2 yards wide.) A four gun battery would take up 50 yards while a six gun battery would span 82 yards. Terrain and other factors would determine the most pragmatic placement.

A2. I'm not sure that there was a specified position to support a battery and would like an answer to that as well. I suppose that it was mostly on the flank, that seems typical in the actions I'm thinking of. Being between the pieces would not be very pleasant, especially during counter battery fire--ouch!

A flank position should be mutually beneficial. A unit attacking either the guns or the supports would be raked by enfilade fire from the other element. Charging the guns would then carry the risk of a counter-charge by the support, and again into the exposed flank of the already disrupted attacker. The threat of that would most likely cause an attack to bog down into a rifle-range exchange, at least for a time. Such a pause would allow the battery time to withdraw if the situation warranted.