i also think that friendly fire is a bad solution (realistic yes, but not really playable)
i startet a new game without a melee, because it was not possible to cast fire or poison on the monsters withouth damaging my own character. even when i have casted it away from my melee, he could not approach the monster that were poisend or on fire. waiting somewhere till it is safe enough cant be the solution.
You have to think more tactically. Cast spells so the edges hit the enemies but not your melee character, cast spells in front of your melee character so that an enemy charging them will be standing on the surface, while the melee character is standing on no surface.
