Thought you'd say that. By way of contrast, here's some real-world pidgin (from West Africa/New Guinea):
Papa belong me-fella, you stop long heaven
All'e sancru 'im name belong you.
Kingdom belong you 'e come...
(Yes, it's the Lord's Prayer.)
Not very comprehensible. Thief's pidgin is reasonably understandable to speakers of English because it nearly is English, and it works by, for example, playing with the -s suffix (e.g. in TDS 'hims' appears to be a subject or object pronoun actually singular in number; in my schema it's a possessive formed by analogy to 'hers' by people who've got the idea that -s is the possessive marker but haven't absorbed the full pronoun rules of standard English). In terms of actual sounds it's less distinctive than, say, Scots or Mummerset, and that's basically the design principle I understood myself to be following.
In terms of the content of what they say, I was conscious of the 'one step away' criticism of Star Trek aliens (Klingons are middle-class Californians who talk about honour a lot, Vulcans are middle-class Californians who talk about logic a lot...) and worried that attempting to accommodate a full rural-barbarian-to-happily-urbanised spectrum would result in: 'I talk about nature and nature spirits a lot, yet I possibly live in a city. I have no particular feelings about this.' (Which would be my main criticism of the script on the previous page.) So I dialled back the Thiefy eco-terrorism and Trickster worship to some vague 'leaf-king' stuff, but tried to make the nature-alignment come through in opinionated comments.