My 2 cents regarding swashbuckling-esque mechanics.
First, Action Points are a must.
Give a lot of leeway on what the characters want to do. If it's cool and swashbuckly, let 'em, even without making them roll for a skill check or, if you really want to encourage such stunts, give them bonuses.
If they want to slide across the slippery deck, in between the invading pirates' legs to come up behind him and poke him with their rapier (or poke him as they go by), let 'em. Jump to the deck of the ship by using their dagger to slow their fall as they cut into the sails? Go for it! Cut curtains and swing into their enemy? Treat it as a charge attack. Unleash a bunch of barrels to fly at the enemy and jump on top of the rolling barrles and "run" along them? No need for a Balance check.
Also, give them environments they can use, and you will be well rewarded (hopefully). Lots of ropes, tables they can jump on, things to use as improvised weapons (perhaps, if it's cool enough, without the improvised weapons penalty), chandeliers hanging from ropes, tapestries placed on walls, stairways (with bannisters wide enough for sliding down), buckets of pitch (for waterproofing the ship's deck, of course), balconies overlooking main rooms (with, of course, a nearby handy rope or tapestry), stacks of crates or barrels, glass windows to throw enemies out of, mugs of piping hot cider or cool beer with a strong alcohol content.
Also, if they come up with something that could feasibly be there that you didn't think about being there, why not have it be there? "He just sundered my rapier? Are there any mops around?"
As for kibitzing on chargen, yes, definitely. I always "define" what is and is not acceptable within my campaigns, even if it's as simple as "no races with an LA, no evil alignments" or "only the races from the Eberron campaign setting are allowed."