One more thing....
About the bow and arrow/guns issue, I have an opinion about it.
As far as guns go, Flintlock pistols do pack a punch. They are very reliable, and it's easy to maintain them. Unfortunately, they take too long and too much attention to reload in the middle of a battle, which is where you're going to be using them.
Putting some logic on this, depending on the material that the gun is made of could also make the gun either better or worse; obviously you wouldn't use a wooden pistol. It's neat, but not safe. Using a more metallic pistol (let's say it made of steel, for example) would make safer, but increase in amount of time a care you have to put into maintain it. This is just with logic, and sense when has the universe of One Piece used logic to this point?
As far as a bow goes, it's very reliable, easy to reload, and like it was said before, you can put different tips on the arrows and effectively become Hawkeye from the marvel universe. That or The Green Arrow, I guess that's your choice. On the other hand, using a bow makes you more susceptible to attacks from behind, cuts off a huge chunk of your vision, and easily becomes warped if you don't take care of it. I know that because I own one. I haven't used it in 5 years, left it sitting in my garage open to the elements, and the damn thing was more like the letter U than a bow.
Also, the arrows are easy to hold, easy to reload onto the bow, and again, can have interchangeable tips. The down side to them is that you run out of arrow very quickly if you aren't careful. They can be retrievable, but always have that chance of breaking off in the thing you shot it into. Even so, they are worth it even to just carry around without a bow just because they can very easily be fixed and replaced.
Honestly, I myself would much prefer a bow and arrows over any other weapon given to me just because I feel more comfortable with it. Guns are handy and the bow is BA. I hope this somewhat helps in deciding which to use.