Your formula gives a starting point of, "f-stop=square root of the ISO, Shutter speed is the reciprocal of the brightness measured in foot-candles squared."

But what if you want a different shutter speed or aperture? You need to adjust them so that the exposure remains the same. That's what I mean by a trade-off.

Of course, you need to do the same with Sunny 16 or any other scheme. The light meter's calculator makes that easy.

With Sunny 16 (light value = 14.67) or a light value (LV) of 15 anything with the highest reflectance will not result in a raw value that is beyond the maximum value in any of the three color channels, i.e., no blown diffuse highlights. In all but the most extreme cases this also applies to the JPEG SOOC.

It's not hard to remember that, if you want to shoot a daylight scene at ISO 400, and f/11, you can set the shutter speed to 1/800 (Sunny 16) or 1/1000 (LV 15).

And it also works for transparency film or any form of negative film where diffuse highlights are impossible to blow.

Excellent post Bob although the terminology could be confusing to those that begin their photographic journey. Sunny 16 works very well in any place of this planet although it requires modifications which are clearly explained depending on the lighting.
An incident exposure meter will place the exposure in the ballpark because it does not keep into account the reflectance of the subject. The spot meter, as you mentioned, is a very precise metering mode in the hands of a skillful photographer.

Digital, as you know is a different media compared to film and with film it is not the same to expose for b&w, color film or slides. Your example of the night shot when you metered from the bright light is the classic example. The important bright areas need to be exposed properly to avoid clipping using digital cameras. Detail lost in the bright areas are very difficult to impossible to get back. The shadow areas on the contrary are more flexible and can be opened up in post in a majority of the cases although noise is a potential problem. I am sure that many members here never worked with b&w film and this media as you already explained requires metering from important shadow areas. Development of the film will take care of the highlights while not loosing shadow details.

Something hard to understand for the beginner is the fact that an exposure meter cannot see tonalities. Exposure meters are designed, as you mentioned for rendering a Zone 5 or middle tone in reading their field of view. A bright or a dark subject will need exposure compensation. Matrix metering compensates the exposure but not even the manufacturer tells us when and by how much. It works pretty good for many subjects but fails miserably with many others. Although exposure compensation is not recommended with matrix, evaluative or multi pattern metering there are times when exposure compensation is needed. Just look at the color histogram to have an accurate representation of the exposure. It tells us how to proceed. Something I can say and you understand it perfectly, center weighted and spot metering are very predictable and those are the types of metering we have been using for years. We know what they do and what we have to do to get the correct exposure, be it film or digital.

As you also said, there are many books about exposure. In my case I got lost in the first few pages with most of them till I found "The Confused Photographer's Guide to Photographic Exposure and the Simplified Zone System" a long title for an easy to read and easy to understand book that will make any photographer an expert in photographic exposure in just one week. Written by the late Bahman Farzad it can be bought today for pennies in the second hand market. It is the best book on exposure that I have ever read.

Thanks Bob for taking the time to show us the intricacies of photographic exposure, one of the most basic concepts to learn when we want better images.