Given the nature of the class and its reliance on dodge AC, I'd also heavily suggest giving them access to Uncanny Dodge I at level 8, and potentially Uncanny dodge II at 14. It would also be worth tossing in Evasion at some point as well, given how much the class focuses on being quick on one's feet.
DuelistsSimilar in nature, the
Duelist class from the PRC offers some other things of flavor:
Of general/existing feats, Duelists get a number for free:
Thug,
Spring Attack,
Improved Initiative, and
Deflect Arrows. Spring Attack is silly for the reasons above, but Improved Initiative and Deflect Arrows both reinforce the fighting style and panache of the class. Plus, Deflect Arrows is just cool.
They also get a few interesting bits unique to the class:
Canny Defense grants the int mod to AC when the character is not wearing armor. This is granted to duelists for free at level 1, and fits the theme very well. Of any of the Duelist abilities, this is the one that would be best fitting as an addition to the Swashbuckler class.
Precise Strike adds extra damage when using finesse weapons. 1d4 per 5 levels of Duelist. Unnecessary if Insightful Strike is being implimented, though Precise Strike is easily superior (if overpowered).
Elaborate Parry is among the most attractive of the if the options, which is somewhat overpowered. You get a bonus to your parry while in parry mode equal to your class level OR a "Defensive fighting mode" that gives a bonus to AC of Class Level+2 to a max of +12 in exchange for a -4 to attack rolls.
Both of these options are probably far too strong in terms of their benefit, but the essence of the concept is actually pretty neat and thematic for what this character is meant to do. A bonus to the Parry skill based on class level (say 1 in 2 or 1 in 4) would give another reason to play a swashbuckler instead of just a dex-based fighter (who will possess so very many more feats), and the parry bonus itself is of fairly limited use. In practice it would only help you hit the parry AC cap early, provide a slight edge when in parry mode (one that can already be exceeded by existing gear). That said, if Swashbuckler Dodge is implemented, this may be superfluous.