Re: Bosses.
The pirate boss idea sounds a lot like Twinblade if you ask me. But a quest could be to infiltrate the ship, fleet, or camp to slay the leader. Or persuade him to stop, or to do something.
I like the idea of long lasting boss-battles. One time when i played Star Wars: Jedi Knight II multiplayer, i had a breathtaking duel against another player. We started in a small room, but the battle did not end in that room. We fenced and i pushed him through a long corridor into a big hall where the fight went on for a few minutes before he killed me. It was breathtaking because it was not slice-block-slice-dead. I had to run and be aware of where i went. That was truly exiting.
One idea could f.ex. be a battle against a human or humanoid, and not a monster. I would have to fence. Mabye start somewhere, and he will run away from me, but i have to follow to kill him. Pherhaps he will try to cross a bridge og something smaller, but i'm stopping him, and we would have to fence on that bridge trying to keep balance as well as defend myself. Kicking is a good feature. The Havoc physics engine will make it possible to make an effect depending on where the kick, or punch hits.
Another idea would be if i hit the opponent in the hand with my cutlass, he will have to shake his hand in pain, run away, or mabye become lesser effective from the handicap.
The battle will continue in many stages until the final blow. Somehow this boss will be killed, or wiped out by you. There should not be only one way to do the final blow, but several. All from cutting off his head, or stab his heart, shot him, throwing something big at him or even kicking him off a cliff or something.
When you finally make that blow, it will make you fell much better about yourself than if you do the same thing on a foe 8 times until his healthbar reaches zero, even his there will be a dramatic cut scene.
Make it like hollywood, i tell you.