When weiting Quark, how did you valance keeping the character likeable with his grey morals? Was it more or less difficult than writing Garak (for the same reasons)?
It was definitely tricky. Quark does some pretty terrible things early in the show, notably in "The Passenger" and "Invasive Procedures," which probably could have made the character deeply unlikeable. I think what mollifies that are a few of things:
Armin is a terrific actor and keeps the character relatable even when doing despicable things.
Quark isn't doing anything wrong by HIS culture. He's a very moral Ferengi and we tried to convey to the audience that everything he did was motivated, at least in part, by his culture. Additionally, Quark evolved over time to become more culturally flexible (settling the strike in "Bar Association" for example) and more "good" from a human perspective.
Quark never means to hurt anyone. Even when he arms bad guys or lets them onto the station, he doesn't directly harm anyone. In his mind, he's just a merchant providing goods and services and it someone does something bad with those goods and services, well, that's on them.
Worth noting, Quark has several redeeming qualities. He loves his family. He's a convivial host and a good listener. He treats his customers relatively well. He's also the least violent character in the entire cast, barring maybe Jake. And he's a snappy dresser!
Quark is funny. Viewers will often forgive the sins of funny characters more readily than humorless ones.
Quark's worse transgressions often backfire on him, making him suffer at least as much as anyone else. This is common with comedic characters and an old trick to keeping them likable.
Quark is, on the balance, more helpful than harmful to the rest of the characters. During the Occupation, Quark helped the Resistance, and while he got paid, he still took tremendous risks on their behalf. In the pilot, Sisko identifies Quark as a key member of the station community, to the point of forcing him to stay. Sisko sees his value and hopefully that helps the audience see it too.
So the creative team spent a good deal of thought and effort on keeping Quark likable despite his misdeeds. I think we succeeded for most viewers, though there are probably many who never warmed to his character.
Still, keeping Quark likable was an effort. It was definitely harder than doing the same for Garak, largely because Garak was recurring and never really a hero. Garak's moral ambiguity is part of his charm. Quark was a regular and viewers, especially back then, expected series regulars to be "good guys." That said, we didn't want Quark to be a pure hero, but we still wanted viewrs to like him. It was definitely, as you say, a balancing act.