I went and got myself confused.
I'm rolling up a Warlock and was digging into how it would work mechanically.
I found out that they are not inhibited by armor for casting in light and medium armor (the only armor Warlock allows) *Armored Sorcerers p140*
Then I read that to cast a spell, shields should be shouldered, weapons sheathed or dropped. You are also considered 'hindered' -2 AC. *Spell Casting p139*
How would say, a Warlock, with a sword (no shield) and an instantaneous touch attack like Shocking Grasp work? I can't seem to find any exceptions for "fighter/mage" hybrids casting in melee, except for clerics. Would the sword need to first be dropped or sheathed, and then a touch attack made? Would you rule that for such a spell, one hand is sufficient? That round's phases for the touch attack would be spent as Cast/Hold, or Hold/Cast, correct?
Let me know what you think!