Frozen over fresh? Probably no differnce at all if well frozen and not freezer-burned.
Beating the **** out of it? Maybe this is an Italian get-out-your-aggression thing but I usually do whack a large one a bit. Tiny ones don't need the smacking.
Tradition says to boil with a cork. Science says it doesn't matter.
Place the octopus in a pot of salted water. Bring to a boil and lower the heat to a simmer. Cook until a fork pierces the flesh easily -- but not until it's mushy.
Drain and let cool until you can handle the beast. Cut into bite-sized pieces.
Great with a sauce of lemon, salt, Italian flat-leaf parsley and olive oil mixed with cubed potatoes. Serve slightly warm or at room temp.
Also excellent with grains such as farro or barley which have been cooked with some seafood stock.