At the risk of belaboring the obvious, Demon's Gate is a fantasy. Its setting is not our own world's Bronze Age, although its geography and climatology are markedly similar. It mirrors European prehistory, but with larger and more developed political units and a higher level of sophistication about certain things, most notably theology. (As far as the latter is concerned, a case can be made for the presence of Zoroastrian-style dualism a thousand years early. After all, in the Demon's Gate world it's real . . . more or less, as Nyrthim would say.) At the same time, the mundane technology of this world—metallurgy, shipbuilding, construction techniques, chariots and their use, and so forth—is as accurate in terms of our current knowledge of the European Bronze Age as conscientious research can make it.
The pronunciation of the various languages is fairly self-explanatory. Final vowels are always sounded. The aa combination in Dovnaan words represents an ah sound shading toward aw. In words of Nimosei derivation (including numerous names and loan-words in Ayoliysei, such as "Ayoliysei" itself), iy approximates a shortened one-syllable form of the sound sometimes rendered as aiee.
I make no apologies for using English units of measurement. Metrics would be even more anachronistic. More anachronistic still would be to put fashionable modern sentiments on such subjects as slavery, war, social equality and gender roles into the mouths of the characters.