Quote from Intex;33065:
Yes it's possible to have 2 statues effects at the same time.
It's possible to have up to FOUR status effects at once. The set I used to use back when I used Ciar Adv. to level had Poison Resistance, Mana Reduction, and Stamina Reduction. I could've added Explosion Resistance by sacrificing a number of +MP enchants, but it wasn't really worth it.
The REAL solution for low defense as a pure mage is as Taran said -- simply don't get hit. If magic is your main fighting style you should practically never receive damage.
Zyrus's method is extreme endgame, but extremely good as well. Definitely not a solution for you at this point though.