Soda being from SoCol.

Fizzy drinks in general conversation.
Soft drinks in formal (ie ordering in a restaurant).

I associate pop with Northerners. Some of them even say fizzy pop.
Perhaps to differentiate between drink and music. It's cute.

Nah. It's to differentiate between 'Fizzy pop' and 'corporation pop' :p

It depends on the context really. I use 'pop' and 'fizzy drink'. I wouldn't say 'I fancy some pop'. I would say ' I fancy a fizzy drink'. But then I would go to the shop and buy a can of pop.

I say soda for the most part.
Coke is a name brand.

Soda is something you mix with, say, scotch.

Coke is a name brand. How can you call 7-Up Coke????? How would they know what to bring you?

They ask:

"Would you like a Coke?"
"Sure?"
"What kind?"
"Orange."

This is a reasonable conversation in the south.