Said sign won't disappear until you beat all the Deadbeat dungeons, which should at least five? (not sure). In any case, the deadbeat status is there to stay for most of the game.
true, (I believe its a cross between a nodachi and a tachi) not sure about that bit, just using estimates on curve and length
Next one has a replica of excalibur
Nope, I'm a cross between a cat and a dragon. (A drat, or a cargon, whichever way you want to see it.)
Next one up has an embarrassing photo of them online