Spoilers abound in the following answers. You've been warned.

What's up with the Baroque Works Officer Agents names?
What are the significance of the birthdays?
What the heck is a tashigi? (general women naming system)
What is Nami's tattoo of?
When and where did Zoro get all his scars?
When and where did Usopp get his sniper goggles?
What are all the Devil Fruit mentioned in One Piece? (ongoing updates)
Why is the Log Pose round?

The women partner of the Baroque Works Officer Agents Pairs take their names from holidays in Japan.  They are supposed to be done in the order of enjoyability.
Miss All-Sunday: All the Sundays of the year at once; like a month of Sundays
Miss Doublefinger: probably the most confusing - a double finger would be 1 and 1 or 1/1.  New Year's Holidays
Miss Goldenweek: A week that usually falls at the end of April and beginning of  May that is filled with Japanese national holidays. 
Miss Merry Christmas: self-explanatory
Miss Valentine's Day: self-explanatory
Miss Father's Day: self-explanatory

Oda uses bird names for many of the women characters in One Piece.  Here are their translations into English
Tashigi: (shigi) snipe, a bird with a very long thin beak that lives in wet areas and is often shot as sport
Kuina: marsh hen
Nojiko: is also a type of bird
Hina: chick
Robin: the cheerful red breast robin, bringer of all things spring-like
Tsuru: a crane

Birthdays:
Luffy is 5/5. This is the holiday called Children's Day (or Boy's Day).
Zoro is 11/11. The phrase 'zoro zoro' means to file along behind, one after another. Hence the repetition of ones.
Nami is 7/3. Na is short for nana is seven and mi is another way of saying three.
Usopp is 4/1. Or April's Fools Day.
Sanji is 3/2. San is one way of saying three and ji is another way to say two.
Chopper is 12/24. Symbolism is usually a little more subtle than this.
Vivi is 2/2. Make the 'V' for victory sign. Do it with both hands. You're holding up two fingers on each hand, right?  Unless you're some kind of freak.  So there you have 2/2.
Nico Robin is 2/2. Ni for two and ko for two.
Hina is 3/3, This is the day of the Hina Matsuri also called Doll's Festival or Girls' Day.
Smoker is 3/15. That's White Day in Japan which is strange because on White Day, it's the men who give gifts to women…

Nami's first tattoo was the mark of the Arlong Pirates. Her second tattoo is a combination of a pinwheel and an orange. The orange symbolizes her foster mother, Bellemere, and the pinwheel symbolizes Genzo, the other parent figure in her life. The blue of Nami's tattoo is like Nojiko's.

Zoro has three prominent scars. The largest one is the one that crosses diagonol across his torso.  That was given to him by Hawk Eyed Mihawk, a Seven Armed Sea he fought during the Baraties Arc.  The scar was also exacerbated by its re-opening at Arlong Park during his fights with the fishmen. The two scars around his ankles he did to himself in an attempt to cut himself out of a wax cake. This was during the Little Garden Arc. Though he has taken many severe injuries throughout the story, it is interesting to note that the only two that left scars were from Mihawk and himself...

Usopp got his goggles from a shop in Loguetown.  While his purchase of this new accessory was not included in the manga due to space constraints, Oda addressed it in an SBS.  Episode #45 is devoted to Usopp's acquisition in the anime.

Gomu Gomu - the eater has all the properties of rubber
Bara Bara - "bara bara" literally means go to pieces; the eater can separate his body parts and have them move independently
Moku Moku -
Sube Sube -
Kilo Kilo - the eater can adjust their weight at will.
Doru Doru -
Baku Baku -
Hito Hito - the eater gains human-like forms. Ioda-sensee said that if a human ate this fruit, they would become more "human-like"
Ushi Ushi - the eater can turn into a cow; the model of this fruit was the Bison
Mera Mera - "blaze blaze" the eater can control fire as well as produce it on his or her body
Mane Mane - the eater can mimic the faces of others
Thorn Thorn
Mogu Mogu - the eater
Tori Tori - the eater can turn into a bird; the model of this fruit was the Falcon
Inu Inu - the eater can turn into a dog; the model of this fruit was the Jackal
Hana Hana - the eater of this fruit can reproduce (flower) their body parts anywhere they wish


Heading up to the bar again.
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