barocca,

I haven't tried flaming arrows, since they are bugged. I leave them to the AI. I've used insane numbers of archers without causing damage as the pachyderms approached--eight units of archer auxilia against base elephants, they didn't rout until they started dying in melee.

I haven't seen the accuracy penalties for archers with deeper ranks. Others have found that box formations work best for horse archers. However, I'm still accustomed to stringing out my archers into shallow lines from earlier TW games, so that is still what I do.