Mage AoE and friendly fire HELP

 wow i keep trying to post this and it is not working

ok, so i want to be a fire mage, but all  the fire spells are AoE and do friendly fire...now...how can i avoid this?

obviously, you will say, move your party members away from the enemies
however, the enemies will just run to my party members, so this is impractical
in the end, i will have to cast spells at both enemies and party members

so, possible ways to negate friendly fire....
force field is one...however it takes 4 skill points and i don't really want to get it
are there any ways to make charachters resistant to, say, fire damage?
if that was possible it would be a great option

are there charachters that are resistant to certain damage?
are there skills that make charachters resitant, or armor?

are there spells i can cast on my team to protect them?

Finally, are there any death penalties for dead teammates?
namely, do i lose anything if i kill a teammate with friendly fire