I think we can divine a few things about the inhabitants of Orussus from this fragment of the
Living ENWorld Encyclopedia.
Note that the most significant building in town is the High Court of Orussus. In pre-human times, this was a temple. Now, if you look at real human history, in most ancient or midieval cities, the largest building in town was either a temple or church of some sort, a palace, a forum (marketplace), a stadium, baths or (near the end of the midieval period) a town hall. The good people of Orussus could have chosen to put the old temple to any of these uses, but they did not. Evidently the rule of law and the institution of the courts is very important to them.
I don't think this is at all at odds with the idea that Orussus is a crossroads town and port, drawing all sorts of strange and chaotic types from hither and yon. While travelers, merchants, and thieves come and go, the permanent residents have to find a way to live with all the hustle and bustle, and still maintain some sort of peace. Given that, I don't find it odd at all that the city proper has a decidedly lawful bent.
In this case, lawfullness doesn't necessarily mean choking bureaucracy. Indeed, that would be the downfall of a busy port and trade center...excessive taxes and regulation would simply drive business to some location near town, but not in it. Rather, I would think Orussus's lawful tendancies to manifest themselves as a strong belief in using the city's standing institutions to solve problems as opposed to an "every man for himself" philosophy. A common creed might be that come what may, so long as the decisions of the High Court are just and all are treated fairly, we'll all find a way to get along.
The consequences of this are that the standing institutions are well provided for, competent, and efficient. I think we've all seen this reflected by the town guard: In Rivenblight's Castaway, they have little interest in affairs outside the city (so long as city affairs are properly tended to), and in the recent duel outside the Red Dragon, the response of the guard was prompt (30 seconds response time) and efficient (all suspects in custody and facing justice after a single round). Further, the justice that the duelists faced was well-honed...they were free to go as soon as they peaceably resolved their dispute, and not one moment before. Although interaction with the city institutions won't always be this slick, we can expect things to generally work well
because the citizens of Orussus care for things to work well.
Now, government by council (probably meeting in an impressive chamber in the High Court) is very appropriate to this sort of city. There are probably longstanding regulations governing how many representatives each guild, group, or organization seats. Also, Orussus is a
free city, which means that it is not beholden to any lord, king or nation, and both considers itself and is considered by others as capable of managing its own affairs. Finally, note that there is no king, emir, or overlord ruling the city...if so, surely his palace would be more noteworthy than the High Court. Perhaps there is a special mansion for the Mayor to live in so long as he holds the post, but this would not be overly ostentatious (perhaps no more than 2 or 3 times the size of a typical wealthy merchant's home) and would not "belong" to him once out of office. I'd also expect the office of mayor to rotate between the various groups, perhaps regulated by statute...