Monsen's right in that virtually everything that tries to equate the Forgotten Realms setting to anything genuinely geographic has been done by the fans only. Part of the problem is that the size of some of the continents were changed at different times, and as the setting developed through various novels written by different people at different times, there was never a single basis on which any of this was hung. It's extremely irritating!

Even the official TSR 1990 "Forgotten Realms Atlas" by the great Karen Wynn Fonstad shows nothing of any latitude and longitude lines, though she does demonstrate very clearly in that just how little of the planet had been even approximately mapped by that time.

The only thing I have come across is a mention on the Candlekeep.com site in their FAQs regarding a map in "Faiths & Avatars" (TSR, 1996) regarding where the equator is. I found that via this discussion post on the Forgotten Realms Wiki site, which mentions the same map shows the canonical lines of lat and long, though so far as I can tell, while there are some lines shown, none have labels attached.

Haven't needed to post elsewhere today as yet, so we'll see how this one goes.

I did find an oddity on the latest "Necro" thread re Cosmographer (Traveller Satellite Size <7) where I lost the vertical scroll-bar, and had to mouse-wheel scroll down to where the new posting was. Partway through doing that though, the scroll-bar reappeared. The other pages with new additions seemed to be fine for this, however.

Also, have you shortened the list of topics shown on the main "Discussions" page? It only covers nine topics now, as well as the five "Announcements" at the top (on the first page only). While that's OK today, there are days when the list of topics added, or added to, since my previous visit almost filled the old-style Discussions page where you could scroll down the list several times. That's going to get tedious very quickly if the number of "new" posts starts running to several pages, especially as I try to read them in order from oldest to newest. It's also going to make it much easier to miss posts by forgetting to check to other pages.

As the medieval wall thickness point has come up a couple of times recently, it may be worth anyone interested reviewing the comments to this query posted on Worldbuilding Stack Exchange back in Dec 2016. The querent was fantasy mapping using CC3. There are some interesting notes there, though perhaps that of greatest relevance relates to an article, The Construction of Medieval and Tudor Houses in London (link is to the free PDF download of the article), which mentions, for instance, an early 13th century London regulation requiring house walls to be built from stone at least 3 feet thick. That not all were seems to have resulted in collapses, hence the regulation. It discusses other materials and construction methods too for the period from circa 1200 to circa 1600, so is worth reviewing.

Most of the other information readily available online relates to medieval castle walls, so is fairly useless for this kind of discussion, but if you dig around, you can find a few architectural and archaeological reports on individual medieval house buildings if sourcing more precise details for specific cases would be useful for your mapping.

As for the Hommlet D&D setting, the original T1 module makes the particular comment from the settlement's heyday (page 2): "Prosperity was great, for the lord of the district was mild and taxed but little. Trade was good, and the land was untroubled by war or outlaws or ravaging beasts." So, plenty of spare cash floating around, it would seem, at least when the original properties were built and enhanced, before disaster overtook things (it's a D&D module; what did you expect?!).

At least after Thursday's livestream, you have the template for making the Creepy Crypt's Cat 😉

As Jim said, there's going to be a lot of personal preference involved here, heavily dependent on how you see your world setting developing, what types of civilizations exist in different places there, as well as how much time and effort you have available for designing and mapping it all.

Plus you're really asking two different, if related, questions - 1) the number of key buildings desirable for different types of settlement, and 2) what the appropriate size of different types of settlement can be for different types and numbers of special buildings.

The question of settlement sizes has come up on the Forum here before, and you might like to look over the comments on these two topics, both of which coincidentally came-up in late 2018:

Making a city with CC3+

Looking for advice on starting Village/Town/City size

There are also various systems for designing RPG settlements available online, some paid for (on sites such as DriveThru RPG), some not (such as blogs), as well as a number of random design systems, such as those on the Watabou site, although those provide primarily maps, rather than lists of the specific places you indicated as of interest.

Those should get you started at least, or perhaps help clarify what it is you want (or even don't want!) from such systems, from where you might feel more confident about creating your own settlement design system.

Good luck!