I think this is pretty silly, and says more about you than the FR, frankly.
The Dales and the North are full of "pale caucasian"-types as the natives, sure, but they're also inhabited by MANY adventurers from foriegn lands, and travellers from afar. This is something that's a key feature of the Realms (and why it's not necessarily a good fit for PoL outside the North), the lengths and depths of trade and traders. Waterdeep is an extremely cosmopolitan city for example, as are many other places in the North and on the Sword Coast.
Traders and adventurers will be the bulk of the "non-locals", and many of them will settle down (indeed, or have specifically done so), not "immigrants and tourists". That's wierd 20th-century nonsense. I don't see much "mass immigration" or even "immigration" in the sense you mean it at all in the FR. Nor is there "tourism" in either the modern or original sense. There's certainly travel and trade, though.
Quit being so pedantic. Tourism = travelers (ie. adventurers/wanderers) and immigrants= emigres (sp?). I didn't claim immigration equals mass immigration. Read exactly and comment on what I actually wrote.
Trade brings various nationalities into contact to be sure. Trade also makes the trade hub cities very diverse and in some rare instances the foreign influence can eclipse that of the native culture. This isn't the norm of course. However, outside of trade hubs, nations generally tend to be homogenous. The more distant from the trade hub, the more homogenous the countryside becomes.
The trading class of non-locals is of the trading class which is always of a limited number and in no way equals the numbers of local common folk. Even when a non-local presence is powerful there are usually wards within a city that become enculturated with a new flavor. This is how is nearly always works. The local ethnic demographic is nearly always far larger than even a strong non-local population. This is as it should be. Only when there is conflict and conquest does a native population find itself ecliped utterly by a non native ethnic demographic.
Cosmopolitan doesn't mean that Waterdeep is as Asian in flavor as the Forbidden City. Cosmoplitan doesn't mean that Waterdeep looks like a spitting image of a major city in Nyambe. Cosmopolitan is a rich diversity that causes a mingling of customs, cultures and boodlines, it does not mean that the non-locals outnumber the locals. This can happen, but I have never seen any indication that in Waterdeep, Baldur's Gate, etc. are more diverse than well mixed trading centers of the medieval era.
Didn't Venice have more Italians as a population than any other ethnic group despite the fact that it was one of the greatest trading cities of all times? I would argue that caucasian Waterdhavians (and the natives of any such city) would naturally outnumber non-locals signifigantly. I don't know what manner of FR you are running but if trading concerns wouldn't be enough to shift the demographics to a degree for non-locals to equal/outnumber native in population...adventurers aren't going to make a dent in the numbers.
So before you decide to question my psychology (I think this is pretty silly,
and says more about you than the FR, frankly) look at the issue logically and demonstrate how mistaken I am.
One way for non-natives to eventually outnumber native populations is via displacement such as the refugees of a kingdom in chaos. However, in such cases, these wouldn't actually displace but would be added to the census rolls if (and its a big if) a city/nation would allow these folks into their domain. They may not because they simply cannot afford to feed thousands of refugees.
I am all for diversity, but I bet you Waterdeep, Silverymoon, Baldur's Gate are largely caucasian just like major cities in Zhakara, Shou Lung, Nyambe, Maztica, etc. are
predominately inhabited by members of the local ethnic/racial demographic.
Wyrmshadows