I wonder if Miqo'te can purr

[CyrilLucifer]

It would seem that, on a biological level though, Miqo'te vocal chords are fundamentally different than most of the other races for them to be able to produce sounds that the others are physically unable to. No different than a human trying to mimic purring but not being able to actually purr.

That doesn't necessarily imply a biological difference between races, because it says "many races" without specification. It implies a difference in accents and manner of speech. You can equally say, by replacing a few words in that sentence:
"Many English speakers cannot accurately reproduce the trilling sound, so they replace it with a r when read."
Or, alternatively:
"Many non-English speakers cannot accurately reproduce the "ing" sound, so the g is going to end up silent when read (In/een instead of ing)." [Note: This is actually an issue, along with some languages and a "th." Alternatively, for a more familiar example, Japanese r/l, they kind of stick with one sound in the middle. Those unfamiliar and just learning the language can't actually hear the difference between "een" and "ing," and some can't pronounce "th" even when they can speak the language perfectly, it ends up more of a "d" sound. This usually happens for non-Germanic and non-romance languages and those who grew up on languages farther from English like, say, Arabic.]

Let me rephrase this, since I'm not sure if I'm getting my point across:
If Miqos are capable of purring, it's because of a change in their vocal chords, which I believe we can agree with because, obviously, humans can't purr and purring occurs in the vocal chords. However, this change would also probably render them incapable of certain other sounds, so they would be incapable of speaking like other Eorzeans. That's how vocal chords work, they are a very precise and finely tuned machine where even the smallest difference can lead to completely different voices and sounds. Even identical twins have different voices.

But we don't see that, we see Miqos speaking pretty much identically to the other races.

If they have put that much thought into linguistics, then they would be quite aware of what I'm saying and it can't just be thrown off as "it's a fantasy game, I can purr if I want to."

This leads me to 2 conclusions:
1. SE really is ignoring anatomy and linguistics because muh fantasy. In which case, they may be capable of purring because it has no basis in reality, in which case asking if they can purr is up to interpretation and the OP of this thread would be pointless, yes?
2. SE is respecting anatomy and attempting to be true to linguistics, in which case they probably can't purr and most definitely wouldn't be purring at the end of a word that ends in r. Or, if they can purr, their speech would sound quite different than a non-Miqo Eorzean, quite possibly rendering them incapable of certain other sounds.

I'd find it more interesting if they actually did have specialized vocal chords that would change their capability of speech compared to the average Eorzean speaker, similar to how a fantasy snake-person with a smaller tongue is generally depicted as making strange, raspy sounds and not just a few extra convenient "cute" sounds. It would add a sort of unique flavor to the very homogenized races this game has. The same goes for the foreign Au Ra, I'd love to have them with some different capabilities of speech completely, due to anatomical differences. Preferably ones that take advantage of their specialized ears, so maybe being capable far lower sounds that are impossible for anyone but other Au Ra to hear. Unfortunately, it doesn't seem to be depicted that way because SE is going for cute and attractive, rather than interesting and unique due to Japan tending to favor the former, rather than the latter.

(unrelated, but linguistics is so fascinating, I am extremely jealous of those who get to study it at a professional level.)