That is actually Excriment. It is him using the toilet.
There is not usually white fluff on a goldfish but there can be white spots which are a sortof fungus you can treat it with things you get from the pet shop
no
"Goldfish" colors range from white to yellow-orange to blue to black. White goldfish have no pigment cells.
Cotton Candy
You might try using a lint brush. That would be effective for removing black fluff from a white shirt.You can also try to use a lint brush.
Not a goldfish anymore.
usually not but it depends on the type of goldfish
no but it does not taste good
It is albino.
no
take it out
goldfish do
white.. I think