i forgot the necessity of the mage staff for fire resistance, good point. however it only give you 1 extra attack dice then your mele attack so is the cost of having it in your book (2 Skill points + 5 mana to take it out then the + 8 mana to re-equipt your lash) for an extra attack dice
i was justifying my choices by the synergy you want with your fire ring and at least 1 fire attack, either the lash of hell fire or a fire spell bound to your wand. since you mentioned the threat of -4 fire resistance you should run just Curse sword and elemental wand, the sword will not have damaged reduced by resistance. and you can get your powerful fire attacks by your elemental wand or alternately your creatures you summoned
true Sectarus will only place a curse if it lands an attack, so i was mistaken thinking you could still cast a creature, but you still get a free action depending on what you do that turn. you could still quick cast a a spell and attack and place a cursed enchantment in 1 turn. it is a more efficient combo if you know your opponent mage is going heavy fire defense
you may only have 1-2 heavy creatures but then why have the other 6 in your book, if your not going to spend the full turn action casting them there is no value in having those skill points invested in them.