If a question is asking for the pronunciation of ALL character/place names in the Westeros universe, then the answers would be unlikely to all fit in a single answer post (30,000 character limit?) As such, that hypothetical question sounds like a textbook case of "too broad":
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once.
Asking for the pronunciation of (say) Aeron Damphair, Petyr Baelish, Jaime, Tyrion, and Cersei would certainly be "multiple distinct questions", and (as we've seen) each of these pronunciation requests can function perfectly well as a question on its own, even attracting multiple answers.
"However you like"
This quote from GRRM is certainly interesting background information on how a given name 'should' be pronounced, but it's by no means the bottom line and only possible answer.
- First of all, it clearly doesn't apply to Game of Thrones questions. For A Song of Ice and Fire, GRRM is the author and creator, and a quote from him can count as "Word of God" (even though I'm pretty sure he's been known to lie or at least embroider the truth). But Game of Thrones is a television show, and as such - regardless of what GRRM says - it does usually have a canonical way to pronounce names, namely the way characters pronounce them on-screen. Admittedly a question asking for GoT pronunciation would probably be poorly researched (although maybe not - consider language/translation issues), but many GoT/aSoIaF questions have both tags, and many OPs will take show info even if they've only read the books. (See also the 3rd point below.)
In fact, the "however you like" doesn't even always apply to A Song of Ice and Fire questions. Sometimes it's possible to deduce pronunciation from context. For example, look at this answer to the Aeron Damphair question:
Damphair is a nickname referring to dousing with water as part of the worship of the Drowned God. So it seems fairly obvious this should be pronounced "Damp hair" (ie. we are saying Aeron's hair is damp). In this case, the "ph" should not be rendered as an "f" sound (Aeron Damfair sounds silly and loses the meaning of wet hair).
That's pretty convincing evidence that the "p" and "h" should be pronounced separately - it makes much more sense in the context of the story to pronounce it that way rather than like an "f". So even if the content creator says we can all pronounce the names however we like, sometimes one pronunciation is objectively better than another.
- Anyway, regardless of what GRRM says, OPs may still find other answers useful. You'll note that neither of the "however you like" answers has been accepted, or even highest-voted. Apparently people find it more useful to learn how the name is pronounced in various adaptations, such as Game of Thrones and audiobooks, than to be given essentially no help at all with how to pronounce the name.
- Finally, of course, "however you like" isn't really practical. Taking this at face value, it would be fine to read A Song of Ice and Fire in its entirety pronouncing Tyrion as "Tomato", Jon Snow as "Eddie Baby", and Winterfell as "the Spanish Inquisition". But nobody would expect you to talk about how Tomato met Eddie Baby at the Spanish Inquisition in book 1; and if you did, they wouldn't understand what you were on about. The postmodernist view that "truth is relative" can be very unhelpful for communication! Even if GRRM says there are no right and wrong pronunciations, that can only reasonably apply within certain parameters.
So yes, "however you like" is Word of God, but that doesn't mean it's the only possible canon answer. There is usually more to be said about pronunciation of names than just that quote - e.g. how the name was pronounced in the TV show, audiobooks, or by GRRM himself, in-story evidence or etymological background supporting one pronunciation over another, etc. etc. As we've seen, even a question about one single name's pronunciation can gather multiple paragraphs of answers. Imagine multiplying that amount of information by the number of different names in the series, and trying to fit all of that into one single 30,000 character answer. It would surely be an impossible task.