The top left is the right one. The right bottom one sends you to a Gradivus Treasure Chest.
The right bottom is the right one.
Battle against Duma. You'll be asked to select 18 units in addition to Alm and Celica in this battle.
Jedah negates eveyr first three attacks, and every fourth attack can only inflict damage to him.
You need to use Falchion to inflict damage when Duma's HP is lower than certain amount.