Yeah, I don't think they're as dumb as you're implying. I don't think the Fire Nation are supremacists or anything, they just want to rule the world. Having a group of earth benders subservient to Ozai would probably tickle his pickle. He probably would reward them just by keeping them around as his enforcers in the conquered Ba Sing Se.
You really think so? I kind of got the impression that the Fire nation were based on ww2 Japan, so they would be supremacists and look down on anyone not of pure fire blood line. Plus the show kind of portrayed it as every nation is homogenously divided and fights against the other, that being the Fire nation since they instigated the war.
Plus don't the dai li have families or ties or anything. I wonder if they feel bad at all.
Thing is, Azula gave me the impression that she's the kind of person who would easily betray them and have them killed once they served their purpose... Then again she was serious when she let Zuko return to the Fire Lord with her in all their glory of victory, so I guess maybe you're right. That one still surprised me, I was sure she'd zap him too and throw him in the same cell as Iroh.