Welcome Rono!
I like to set autopause only to activate when an enemy is sighted and when a trap is detected. I find pausing after each round to be tedious. Too much pausing... I have also occasionally set it to pause after each enemy is destroyed...but I don't leave it like that for long, usually.
AI? I typically utilize the defensive scripts that call out missile weapon use first and then melee when the enemy is too close to utilize missile weapons effectively. However, I typically turn the AI off as I can handle my party pretty well without it.
I typically turn the AI off when in battle.
Hope that helps!
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Now where did I leave that doughnut?!