If you want advice on how to dual-wield better, I'm afraid I won't be of much help. I've always used a single long sword. But I will say this: It's something that can be learned, and once you've learned it, it'll be more effective than at least juggling weapons.

[ Switching between sword and staff constantly just sounds like a pain. Neither of them seem to have a real advantage over the other at specific ranges, and counting down until the sword runs out of mana is just unnecessary mental burden. ]

Practice is probably the only option for you. Mastery through repetition, that's how it works for most people.