The first thing I notice as I go through these language and world descriptions is that we have some humans involved, and a goodly number of humanoids. All cool. I note that Catreona has her humans speaking "British," which is the language represented by the English used for the story. This is a good way to organize a human language in this context. For example, Sheila Finch calls her human language "Inglis." This is an important thing to address if your world is divorced in space and time from our world. If you choose "English," that will mean the language is the direct descendant of modern English and will probably not be a uniform Human language but one spoken by a segment of the human population.
K, if you don't yet have a name for your human language, I'd suggest you pick one. If you're calling your humans Terrans, maybe "Terran" should be what you use.
I don't see much on human language in David's piece. David, have you got your human language worked out in some basic way?
More individual questions (please everyone read):
For pyraxis: You say that rsakk are one of several races of "human," but that they shift into lizard form and others shift into other forms. While I can see how fire could be important to these people (especially if they breathe it, it might be seen as an essence of their spirit), it seems to me that the main distinction between them and others is that they take the lizard form, and that this would figure hugely in their cultural identity and language. Are there any special characteristics of rsakki that make it pronounceable by or otherwise appropriate for lizards (rather than others)? Do the rsakk feel that their lizard form is purer or otherwise better than their human form? What is the role of human form in their lives as opposed to lizard form? In what contexts do they want to differentiate themselves from the other types of people?
For wordjinn: You say the three houses, Az, Uz, and Ua, are separate and concerned with different things, and they have dialectal differences but not major language differences. I wonder how, and how often, the three houses interact with one another. This would be a factor in evening out language differences. Since they've obviously been around for a long time, I could see that there might be dialectal distinctions between the groups. Can you think of a way to make the language use reflect the main concern of the house? I should remark that dialectal differences can be rather large, and if you want there to be dialect differences, you should probably think of how you'd like to mark them in your English text. Also, if Ua is a "newer" house, then its dialect might resemble one of the others (say, Az) more closely than the two others do (making Uz and Ua dialects more similar to each other than to Az).Do you have any immediate thoughts on this?
For K: can you clarify the psychic powers of the Dalkans vs. Eyans? What kind of psychic behavior is expected in social contexts? Is there a principled way in which the provision of empathic cues fits in with the Eyan (or Dalkan) language? I imagine there could be, if these people are accustomed to having an emotional overcurrent surrounding them. Your excerpt from the worldbuilding workshop said things about the ability to block emotional projection. Does this have degrees? What kind of empathic behavior is expected in different social situations?
For Catreona: I need to know more about the interaction of your people. Based on your excerpt from the worldbuilding workshop, I have the impression that they conform to the social rules of the British, at least roughly. I would expect, though, that the nature of the task of surviving and making society work on this foreign planet would alter some things about it. What might those things be? I would also encourage you to think through the situation of the Plague Children, since it seems to factor significantly in your story. You say that the Plague Children are well-integrated (and so are the indigenes). I would expect that the society as a whole would then hold an ideal for such integration, as well as maintaining expectations about how such people are to be treated, addressed, etc. Once you've figured out what this is, you'll then be able to get a better sense of what unwanted discrimination means. People will not all hold these ideals to the same degree. If you're interested, you might want to check out my entry entitled "Don't make them all the same." I'd like to hear your thoughts on these topics.
For David: It sounds to me like you're looking to create a language with a distinct system of formality. The parameters for your formality and informality are not clear. "Respectful" informal language can be as simple as speaking informally when the situation calls for it. Are you looking for something that is spoken asymmetrically based on rank, or something that is spoken symmetrically based on the formality of the situation, where having a person of high rank involved would cause both parties to speak formally? Next, here's an issue that's been bothering me since the last workshop. Have you worked out the precise circumstances of the change from land to water habitation? This will have a huge influence on the language solution that was pursued by these people. I tend to think that they would be likely to have a sign language. This would lend itself well to your semi-translated words. Water as a language medium is very limiting because of the type of sounds that travel - think about dolphin and whale communication. If you want humans to try to speak a vocal language of this type, it will be a challenge. You can pick a vocal language that sounds different above and below water, but I would think that the sounds that are inaudible or indistinguishable underwater would regularize and disappear rather quickly under those conditions. The pheromone discharge strikes me (at first glance) as totally unnecessary. There will be lots of opportunities for communication difficulty already, and I'm not sure how they would evolve naturally. Again, please tell me more about the history of the inundation. I look forward to hearing your thoughts.
Everyone please feel welcome to read each other's material and comment on your own initial impressions. I will continue to make comments as I find new things to comment about. Your written responses to these questions will help me a lot.