"I thought the camera and flash talked to each other (with the SB800) in the hot shoe. And that setting parameters on one or the other, limited parameters on the other. In other words, Matrix wouldn't be allowed when in TTl mode. And, correspondingly, TTl-bl wouldn't be allowed if camera metering were to set on Center or Spot."
Your misunderstanding of the camera/flash communication has been addressed several times in this thread and the similar post you made in the D7000 forum. The camera and flash do talk together, but setting parameters on the flash will not change the setting on the camera. That relationship only works one way - the camera settings will change the settings on the flash from TTL BL to TTL, but setting TTL on the flash WILL NOT change the metering mode on the camera - and it isn't necessary.
There are lots of times when you might want to use TTL instead of TTL BL with matrix or CW metering, and you wouldn't want the flash to tell you that you couldn't do it. On the other hand, when you are in spot metering mode, you aren't metering enough of the scene for TTL BL to work, so selecting that metering mode on the camera causes the flash to revert to TTL if you had previously selected TTL BL because the flash couldn't give you a balanced solution anyway.
If you set the mode on your flash to TTL, and you set your camera to ISO 100, Manual exposure, f/9, 1/250, auto white balance, you should be able to achieve the results you want unless the ambient incandescent light is extremely bright. It is possible to get warm ambient light in the background (though it shouldn't be much of a problem at those settings). If warm light in the background is objectionable, you can always gel your flash to match the temperature of the ambient light and then select a tungsten white balance or set a custom white balance that will guarantee there is not warm light messing up your shot.
Trial and error method: Turn your flash off, set your camera on manual exposure and take a shot. Pick any metering mode you want: spot, CW, or matrix. Adjust ISO, aperture, and/or shutter speed until taking a shot produces nothing but a black frame. Leave those settings on your camera, turn your flash on, make sure it is set to TTL and take a shot. I guarantee you that no ambient light will be added to the scene.