I've read some of the previous thread on the subject (11 pages is quite a bit when you have a school bus to drive in a town an hour away). One thing I didn't see asked at least as yet is something about a writing system.
I just created the thread as kind of a mental exercise because I like thinking about these kinds of things. I watched a YouTube by a guy who goes by Artefexian about building a "conlang", which is what Dwarfish would be (until I know what the name of the language is I'll just call it that). One of the more interesting parts to me was the writing system, which is shaped in most part by the medium in which one writes. Up until the last major update came out with books and scrolls and papermaking, I had assumed that the medium would be stone, or possibly clay, since it seemed that most of the written communication occurred in slabs and engravings and crafts. If we wanted to look at the updates as a sort of historical progression of their writing form, would we assume the writing system they use would be mostly straight lines that lend themselves to carving more quickly and efficiently?
Also, with Dwarves being more of a showy sort when it comes to something etched in rock, with people becoming legendary engravers and the sort, I would think their language would probably be some sort of logographic text, like the Hieroglyphs of Egypt in our world. Remember, these are just theories. It appears that the linguistic part of DF is something that Toady wants to do personally, like Tolkien did, but there's no reason we couldn't have fun with this kind of thinking.
Diacritics is something I'm only just now learning about myself as relates to language, since the languages I am fluent in do not make use of them. I'm currently learning Arabic, which uses diacritics to denote the vowel sounds (or in some cases lack thereof). Since the text we have uses the Roman Alphabet, which I doubt would exist in the DF world, and we have no clue what exactly the alphabet would look like, I have a few theories:
1. Elves would probably use a flowing curvy script with few straight lines. I theorize this because the hippies would probably use leaves to write on, and straight lines tend to tear the weak material. This would still be true if they used something like brushes as utensils for writing, since that is more conducive to flowing lines.
2. Dwarves, as I said earlier, would probably have a more straight-line based writing system, possibly logographic, with maybe a featural alphabet to supplement the primary logographs (think the Korean writing system in the transition period when Hangul was first introduced). I would think it might look something like the Cuneiform alphabet, because the writing medium will heavily influence the alphabet. Now this might be different if we assume that dwarves had paper writing from the beginning as it shows in world-gen, since you can literally begin making paper in the first year.
3. I'm not a good adventurer in game, so I don't get much information on the culture of humans and their writing mediums in game, and even more so for the goblins, since getting to explore a goblin fort requires surviving a fight with the goblins which requires not starving to death before you get the party or skills to survive the attack. I'm not yet very good at that. I'm more of a fortress guy.