"Straight from the fridge" is Jazz-era (1920s and 30s) slang for "cool." "Daddy-O" or "daddio" is, as you said, the Beatnik equivalent of "dude."
The American Jazz and Blues musicians of the 1920s and 30s developed their own sort of language, a lot of which influenced the slang of the 1950s and 60s. It was quite colorful and expressive - for example, instead of simply saying "be careful, that could kill you," they'd say "be careful, or you'll have six friends carrying you by the handles. (referring to a coffin)"
Obviously, a lot of it sounds hopelessly dated now, just like "far out" and "groovy" do. But that doesn't bother some of us hepcats. Plant you now, dig you later!
