thanks everyone for helping
i'll reconsider my build
@
http://www.enworld.org/forum/members/streamofthesky.htmlStreamOfTheSky: i can't buy off the level adjustment and i can't use tome of battle
only
Player's Handbook
Player's Handbook 2
Dungeon Master Guide
all Complete x books
and what about basic stats? should i invest more on constitution? any suggestions on the basic abilities stat allocation?
What are your starting funds (gp), and you don't get Magic Item Compendium for choosing gear? That's important -- MIC has the Mobility enhancement for light armor as a +1 market price. +2 armor is affordable by ECL 6 (4 class levels, 2 LA). Very affordable if you have standard wealth, which you may not based on what you said earlier. Dervish is a great class for Swashbucklers, but requires a lot of feats, including some crappy ones. Dodge, Mobility, Weapon Focus (any slashing melee weapon, if possible pick scimitar for later on), and Combat Expertise.
The good news is, it looks like you were going that direction with feats anyway. Still, paying for Mobility hurts, and might make it hard to enter the PrC as soon as you can -- you only need BAB +5 and 3 ranks in some skills otherwise -- I'd grab those 4 feats first, then TWF and Deadly Defense, and later on perhaps the higher TWF feats. If flaws aren't an option and neither is the Mobility enhancement (worth begging for it, just to save 3 levels, if at all possible), then you can't go into Dervish until Swash 9 / Dervish x, sadly.
Dervish is a great class, it gives Dervish Dance, which lets you move between each attack of a full attack. It lets you weild scimitars as if they were a light weapon, handy for both Insightful Strike and TWF penalties (and Deadly Defense). Always take 10 on Tumble, Jump, and dance checks, small AC boost, small movement speed boost, free spring attack feat, a parry bonus when fighting defensively, iniative bonus... The level 10 capstone lets you 1/day double your number of attacks on a full attack, which is unbelievably sexy.
I reiterate that you should grab Arcane Stunt. Getting Blur or Expeditious Retreat for 1 round, 4 or more times a day, is almost certainly better than +1 reflex saves. Definitely more fun.
EDIT: And yes, Insightful Strike and Deadly Defense both work with two weapons, and it's probably the best way to utilize them.