As mentioned, I read this some time ago. From what I remember, the sense that crimes are acceptable is very much a class thing -- the rich and pampered feeling that they can get away with anything because of who they are, an attitude which repels Glawen Clattuc, the central character -- but I seem to think that most of the wrong-doers get their come-uppance by the end.
Yes. laws on Araminta Station are a little skewed, due to its somewhat unique status as a 'Preserve' (I think that was the term), a status which becomes central to the plot as the series progresses and goes beyond Araminta itself.
It's interesting that you talk about Vance's fantasy books as being famous. I've read all the Dying Earth books and the Lyonnesse trilogy and enjoyed them thoroughly, but I still tend to think of Vance as primarily an SF writer, having read 20-odd of his science fiction books, many of them (including the Cadwal Chronicles) set in that strange sector of space known as the Gaean Reach.
Must confess, I don't recall being troubled by the sort of issues you raise when I read Araminta Station, I just remember revelling in Vance's glorious use of language and marvelling at the strange and vivid world his words create.