Her original, HW, and New Years forms are best used in a Divina Attack team
Her Focused form is best used in a Divina defense team
The [HW] form is dressed up as a Witch.
The [New Years] form is most probably dressed up as a Miko (Shrine Maiden).
Normal Ameno Uzume appears in the "En garde! Ghost Agents Do Battle!" picture.
Normal Ameno Uzume is one of the starters in the game.
She was originally planned to have been able to transmigrate, but this was either scrapped, replaced by her Focused form, or stored away for future use. 
In the "Ancient Japan's Got Talent!" Event, She, Satori, and Mira form a dance group called the Mi-Sa-Me Megastars. The groups' name takes one part of each ghost's name, meaning the Me comes from the last part of Uzume.
Main: "Coo-ey! Won't you come over here and dance with me?"
Skill: "Look at me shimmy!"
Main: "Halloween's a great excuse for a party... I'm really getting into the mood!"
Encounter in Shop: "En? Seems like everyone's face is filled with joy and smile!"
Skill: "Check out my new dance move!"
Main: "Happy new year! I look forward to another year of entertaining everyone with my dancing!"
Encounter in Shop (New Year): "Happy New Year! This is fantastic! How about we celebrate with a little dance!"
Encounter in Shop (Anniversary): "<Player's Name>, happy anniversary! How about a dance together?"
Skill: "My new year's resolution? Dance some more!"
Main: "Hold on, Ammie! I'll have you out of there in no time!"
Skill: "You've never seen anything like my dance!"
Main: "Watch my marvelous dance!"
Skill: "Ooh...this feels so good!"
Encounter in Shop: "You haven't been practicing your dancing at all, have you?"
Unseal: "And now for the right foot..." A goddess with extraordinary artistic talents. She imprisoned herself in a sealstone and fell into a deep sleep.