Other thoughts on Dual Wield...
How to handle the CS bonus of powerful weapons or high level skill if they both count for both hands?
For example, a Scion-Kai with Weaponmastery Dagger gets +4CS but his fellow Kai with Psi-Surge also gets +4CS but at -2EP/Round, not so great unless they are captured and weapons taken. What happens if you get your Weaponmastery bonus with both weapons? Well in the above example the first Kai only has to spend a couple of Crowns to buy another Dagger giving him +8CS if dual wielded! No-one would want Psi-Surge until Archmaster!
Another example, Bk 28 Grand Master (for arguments sake WITHOUT Grand Weaponmastery so we don't get confused on slots/Sun Knight using one handed two handed weapons, etc.). Their Kai Weapon is a Broadsword (30% chance). They pick up Sunderer, +5CS Dwarf Battle Axe, and Andarin Warhammer +5CS also. Assuming the Battle Axe is one handed, and Joe does not say otherwise, dual wielding gives +10CS whereas th 'measly' Kai Broadsword is just +5CS.
On the subject of this why is everyone saying you cannot use a Shield with a Broadsword, etc.? I decided with Beserk/Defend you couldn't because you need greater flexibility but it does not say anywhere you cannot use one with a two handed weapon in normal combat. I think we all play various games systems and it is easy to assume what is true for one or two is true for all - where does it officially say different? Keep shields for normal two handed weapon use otherwise they'll be even less reason to use them... unless you can double your Weaponskill bonus, etc. with two handed weapons used two handed and claim your Weaponskill bonus for each weapon when dual wielded... (still does not solve the 2 +5CS one handed swords vs 1 +5CS Broadsword dilemma).
Okay, how about -
2 Handed Weapon (beserk) - Weaponskill, Mastery, etc. bonus DOUBLED (concentration & flexibility required = no psychic attacks/shield).
1 Handed Weapon in each hand (concentration & flexibility = no psychic attacks/no shield) - Claim Weaponmastery bonus + Weapon bonus for Primary Weapon and averaged weaponmastery bonus + weapon bonus for offhand weapon.
So anyone without Weaponmastery will want a normal shield still whereas those more skilled would want to dual wield or use two handed weapons unless they have a magic shield, seems reasonable.