So, this all sounds pretty plausible to me, even likely. Eorzean is the "common tongue" however, Fernehalwes mentioned that each race has its own language (and likely even different dialects of it within that) but that most of these languages are older and either not spoken as frequently as they once were or forgotten entirely.
The common examples were brought up in the Naming Conventions threads for Roegadyn and Miqo'te specifically, wherein both races had a more ancient language that had since been mostly forgotten, but their naming conventions and such were left over from it. Miqo'te had that guttural hissing language that no other race could emulate and Roegadyn had well... Roegadyn? I don't recall what the language was called if it even had a name.
Each of the Beast Tribes also has their own language. Sylphic, High Sylphic, etc. The Sahagin's language is called "Bloodcant" and several Reavers and Sea Wolf pirates learned to speak it in 1.0.
So I think an insular Miqo'te Tribe would actually have its own dialect separate from Common Tongue or even other Miqo'te, even if only by a little. So definitely play with it! ^^ Would like to RP with your character sometime and hear it!
The common examples were brought up in the Naming Conventions threads for Roegadyn and Miqo'te specifically, wherein both races had a more ancient language that had since been mostly forgotten, but their naming conventions and such were left over from it. Miqo'te had that guttural hissing language that no other race could emulate and Roegadyn had well... Roegadyn? I don't recall what the language was called if it even had a name.
Each of the Beast Tribes also has their own language. Sylphic, High Sylphic, etc. The Sahagin's language is called "Bloodcant" and several Reavers and Sea Wolf pirates learned to speak it in 1.0.
So I think an insular Miqo'te Tribe would actually have its own dialect separate from Common Tongue or even other Miqo'te, even if only by a little. So definitely play with it! ^^ Would like to RP with your character sometime and hear it!