Multiple weapons eh, the weaknesses are:
Reduced reach - The only one handed reach weapons are either weak or obscure, and all exotic.
Strong Dex requirements
-Lower Str(due to stat split)
-Lower AC(due to heavy armor restrictions)
-Restrictions on buffs. The easiest sources of damage increase, sizing up, might screw you up.
Heavy feat investment
-The TWF chain, and if you want to hit, Weapon Finesse
-The shield chain if you're using shields instead of paired light weapons.
Lower to-hit. If you're using TWF, you stack the -2/-2 with iterative penalties on later attacks.
Loss of Power Attack, using a light weapon in at least one hand means you are halving the benefit while doubling the cost. Using two light weapons rule it out entirely(barring twin 1H styles)
Cost. All multiweapon styles are expensive. Weapons are already the most expensive enchantment.
-Straight TWF buys enchantments for two weapons
-S&B buys enchantments for two weapons and a shield.
-Natural weapon styles makes use of one of the less efficient weapon enhancers, the Amulet of Mighty Fists. The ratio does improve when you have a bajillion of natural weapons though.
-Poison/Flask styles have a problem with staying supplied. It costs quite a bit per shot.
Weight. Due to weaker Str and preserving encumbrance, inventory management may be an issue at lower levels
-Flasks are heavy, you can probably chuck up to your light load of them in a round easily.
Requires full attacks. Admittedly a problem with everything but archery and ubercharging, you need to be based with an enemy to do something. Weaker AC is going to sting.
Vulnerable to special attacks, most of the ones that target weapons will be looking at weapon size and str. Yours are tiny and your arms are weak.
Strengths:
A bajillion attacks.
-If you can hit at all, you will. Very rarely would you fail to do damage entirely.
-If you are crit fishing for triggers, you will too.
-Anything which enhances multiple attacks get royally boosted.
--Sneak attacks and other on-demand precision damage sources go straight through the roof if you hit.
--Bonus damage enhancements count for a hell of a lot more. The <energy> Burst enchants might as actually see some use.
--General buffs see the same benefit. A +2 to hit goes a lot further when you have a lower to-hit from TWFing and weaker attack stats in general. And then theres adding bards.
Mitigation:
If you have a source of Greater Magic Weapon/Greater Magic Fang/Greater Mighty Whallop, it takes the burden of costs off your shoulders.
Dex dependency can be voided(and thus many associated flaws) by using the Agile Shield Fighter or Natural Weapon methods.
Work on your strengths. Get precision damage, high criticals, whatever. Magnify those.
Get pounce or something like it to deal with lower defenses. In any of these forms you are a natural for alpha strikes.
Get concealment or some other means to void damage while you close in. Can't hit if they don't know you're there.