Q: What are the rules for a flank attack, does a unit start behind a line drawn from the front edge of the target Unit's bases?
A: A flank attack can be defined as one delivered from outside the defender's frontal 45 degree firing arc.
Q: When a Defender with a supporting line is attacked by an Attacker who can overlap his front line, does the support line physically move onto the flank or stay in line and count as flanking?
A: It would move to meet the Attacker's overlapping stand… you'd have what would amount to two “L's”, one inside the other
Q: In Phase 2 of the melee, the rules say that all non-committed infantry stands within 1 inch of the engaged units may be moved into contact and counted. Is that within 1 inch of the melee or 1 inch of the enemy? And what is their movement limit? 1 inch?
A: Within one inch of the engaged units means within one inch behind or beside the stands that engaged in the first phase. The movement is theoretically still the normal line movement rate, but in actuality, anyone within an inch will only have a very short distance to travel before he runs into someone unfriendly!
Q: For a cavalry support line, they can engage and be counted if within 2” …so could the cavalry support line sweep onto flanks and envelop their enemy… and would this be counted as a flank attack?
A: They could sweep around to engage, but this wouldn't could as a flank attack -- supposedly by the time the units are into Phase 2 of a melee, there’s not much of a flank anymore… that’s why only two modifiers are counted in the Phase 2 melee (cuirassiers and superior morale). If there’s enough spare stands to actually envelop the enemy, that will eliminate him if he loses the melee, though.
Q: Since morale is normally tested by cavalry brigade, if one cavalry regiment charges does any morale result affect the rest of the brigade, even if it is a ways away?
A: No, if the brigade is operating as separate regiments, it'll test morale as individual regiments.