Malcolm is being played just fine as is, but since I suspect you'll not totally listen to this first line, I'll address your points in more detail.
First, the State does present a unified face to outsiders. You're doin it rite. The reason Katrina for example seems so separated is because Ishukone under the current status quo is the black sheep. They're not welcome in most places unlike Wiyrkomi, so it makes sense that they would be looking out for their own interests and seeing themselves as a bit more independent. Those working for the Patriot bloc likely never experience the social blocks put in place against Ishukone by Heth because they simply don't encounter them. I would wager Mal has no idea how hard it's getting for Ishukone unless he's specifically reading about it.
The State is supposed to be one unified voice, but only those who are being ostracized would start to act differently. Kat would be just like Malcolm in this respect if she wasn't Ishukone - if she didn't have to walk on eggshells to avoid drawing the attention of the CPD. Remember, Kat lives with her female fiance on New Caldari V. The Provists could storm her house and drag her away at any moment if she makes waves. This is why she's suspicious of everyone not Ishukone.
As for the debate thing, as I posted in another thread, that was an IC reason to avoid getting caught doing something I'm not particularly good at. To me it makes sense, but this doesn't mean you're doing it wrong. Malcolm could be very interested in something he considers worth his time like debating and debunking stereotypes and bad rumors about the State. That's what it's about there - perception of worth. Kat doesn't see fencing words to be worth her time, but Malcolm does. If you enjoy it, who am I or anyone else to say that's wrong?