My analysis:
“Good morning, Mayor!” - Isabelle, obviously
“Not bad, that's what I was looking for.” - PROBABLY Elma??
“I know it's hot but make sure to wear the mask on the back of your head, it likes to strike when you aren't looking.” - Skull Kid
“The sun, moon, and stars may align in a way that finds Venus favorable.” - Isaac
“Anyone who gets in my way is my enemy.” - Shadow
“Completely in the dark, eh? Well, it's a big mess up there right now, and it concerns you too!” - Bandana Waddle Dee...?
“Look above! They've been testing those three for awhile now! We will have to dig deeper for more though...” - “Those three”, so Chorus Kids
No idea on the rest
Oh, there's already a list
"Good Morning, Mayor"
-Isabelle
"Not bad, that's what I was looking for." -
Ken
"I know it's hot but make sure to wear the mask on the back of your head, it likes to strike when you aren't looking."
"Look above! They've been testing those three for awhile now! We will have to dig deeper for more though..." -
"Spirits have a tendency to be sticky, who knows what pedestal they will rest on?" -
"Well whatever. Even if they were to come now, they wouldn't be able to handle me."
- Skull Kid
"Many tricks are up my sleeve, to save yourself you'd better leave!"
-Banjo (Gruntilda)
"Completely in the dark, eh? Well, it's a big mess up there right now, and it concerns you too!"
-- Geno?
"The sun, moon, and stars may align in a way that finds Venus favorable."
-Isaac
"Anyone who gets in my way is my enemy."
- Shadow
"Never mind. Don't have time. I'm late enough as it is!"
--Bandanna Dee
"If only we could be more like these coins..always smiling, regardless of which side we land on."
--- Rhythm Heaven
"Are there secret caves?"
--Dixie
One of the three that doesn't have one is Jin Kazama from tekken, and one of them is probably a Pokemon quote.