Boning a limp fish

I haven’t been very cryptic lately, so here are a coupla riddles clumsily wrapped in an enigma: Which shallow thinker was exposed by one of my Twitterspondents who was shocked to find that in person he had nothing, original or otherwise, to say about the big issues he natters on about? Which food-world hero loves a parrot when it repeats just what he says but through a very big megaphone? As far as I know, the ST does not sleep in the boss’s den, so how do those juices “leech”?