The way freyar described it is the way I always understood double weapons and TWF to work.
Even if we skip the TWF route, I'd still prefer the sickle, despite the lower damage output, as these are primarily enchantresses and illusionists, not melee brawlers.
...and a kukri is better than a sickle how?
That sounds good, and I think I prefer enchantment to illusion.
For the skills, maybe Bluff, Concentration, Disguise, Hide, Knowledge (arcana), Knowledge (nature), Move Silently, Spellcraft, Use Magic Device?