I had forgotten about the insightful attack bonus that stacks with str. so that part of my question is answered.  Now I am left with this...
Keeping in mind that Weapon Finesse is a class skill of the swashbuckler, and I would not want to waste it, how do I make a one-handed weapon, into a light weapon.  
This is an issue because... I am trying to two-weapon fight with dual tridents.  Oversized two weapon fighting is easy enough to attain (we are on a point buy system so upping str. is a no brainer) which makes my offhand trident into a light weapon.  Why the crap is there a feat that turns my offhand weapon into a light weapon, but not one that turns my main hand weapon into a light weapon?  Apparently I am not supposed to be trying to two weapon fight with weapon finesse... I digress.
So far the only solution that I can think of is using the first suggestion of feycraft in DMII.  I take monkey grip to be able to use larger weapons, than get a feycrafted large sized trident (+1500 gp to whatever it costs to make a large trident).  That would enable the trident that I use in my main hand to stay a 1d8 instead of dropping not only a weapon category but a size category as well.  
That makes me head hurt... and I feel like there should be an easy way around the whole light weapon issue, anyone have any other ideas?  (again this is only because swashbuckler has weapon finesse as a class ability that I am in this situation.  I like everything else with the swashbuckler, including flavor, but can't get around this one issue.)