The cursing on Executor only affects you while wearing it. You should definitely use Executor in either case (note my sig). Cursing is a very weak effect at this point in the game, and humanoid slaying is a very big effect. Feed the battle axe to a rust monster.
Reading the scroll of peace might help, but a single scroll probably isn't enough to have a big effect... by D:39 or whatever Air Temple is on, pretty much all monsters are available for summon. If you had 10 scrolls of peace, you'd probably see a nice difference, I guess. The majority of the time the Air Temple is very easy, so don't sweat it too much.
Hoping to win with every class, doomed. Archer, Barbarian, Bard, Beastfighter, Druid, Elementalist, Farmer, Fighter, Monk, and ULE Priest down.