I'm just going to be an asshole and comment that mages SUCK for Lord Missions.
Sorry! XP
Not if you have the right party, half the battle of being a mage is running things with people who understand the spells, however by the sounds of it you don't have magic ranked or you would know how to deal in harder missions.
Fireball is a very useful skill in nearly every situation if you know when to switch to another, even Hailstorm is the same way, very high damage output. If you are a mage and struggle with parties then you need to explain how certain magic works to most people.
For example 95% of mages will thunder a monster just to have someone run up and smash it because they don't KNOW that it cancels some of the thunder charges by doing that. Or don't realize not to windmill in the middle of a group when someone is trying to drop a fireball. On top of that if you have a good mage with lets see, my mana pool can get up to 800 and I've got rank 6 mana shield that scales off of my int, with the mass amount of potions I make for myself, I don't die, AND I can even tank multiagro that most can't because of it, allowing for others to regroup, revive and heal while I'm tanking.
TL;DR if you think mages suck at lord missions, either you haven't had a mage that KNOWS what they are doing, or your running with an ignorant party that doesn't know how to adjust for magic.