Ira Behr was a big fan of Iggy Pop/Iggy and the Stooges, and had pushed for Iggy to be cast earlier in "Past Tense, Part II"; Iggy was unavailable at the time and the part went instead to Clint Howard. No, Yelgrun was the other Vorta in "The Magnificent Ferengi". http://memory-alpha.org/en/wiki/Iggy_Pop
The Vorta embody bureaucratic phonies. Kilana was slimey, too, you just bought into her pretense. Weyoun was the gold standard. It was fun watching the contrast between blunt Cardassian arrogance and the Vorta's civil veneer.