It seems like everything has been updated with Bards, except for the Swashbuckler enhancement tree. As a previous fencer in RL, this is my favorite type of character to play, so could this please be updated as well? I don't think this needs a major re-working. Some ideas I have are as follows:

Tier 1: Change “Insults” to “Fencing”
I’ve never found “Insults” to be terribly useful. Instead, change this to the “Fencing” enhancement, which is comparable to the Vistani knife fighting enhancement in that it changes the combat moves you use. "Fencing" would be: When “Swashbuckling” you now fight in melee using the classic fencing fighting style (ex. using lunges instead of swinging your whole arm, which would get you hit in a real sword fight). I realize this might be beyond the scope of work that the developers want to do, but it would be really cool.

Tier 2 – Reduce “Sword Dance” AP cost
This just doesn't do enough damage at 2 AP/tier. Change this to 2 AP for the tier 3 ability, or reduce the AP cost to 1 AP/tier.

Tier 4 – Reduce “On the Mark” AP cost
This is way too expensive at 2 AP/tier (i.e. it is suboptimal). Reduce this to 1 AP/tier.

Tier 4: Change “Wind at My Back”
You just don’t do a lot of damage with a throwing dagger, and I really only use it to hit a target, or get something's attention. It would be cool if this had synergy with the Vistani "Weapon Versatility" enhancement. So perhaps change this to use your doublestrike instead of doubleshot if doublestrike is higher, when using a throwing dagger.