Prologue:
I was idly thinking about computer games, as I often do, when I had an idea. The "real" FOV for a game, the angle that renders the word such that it is as though one's monitor is a window into the world, can be worked out trigonometrically using the width of your screen and the distance you habitually sit from it. The value (in degrees, for gaming) is equal to 2arctan[(width/2)/distance]. This value should be more immersive, by making estimation of size and distance more natural, and by removing the hints of fisheye at the edge of the screen.
When I got home, I moved my 19'' monitor as close to the edge of desk as I could stand, measured the distance to my eyes, and calculated the value: 53.13, which is a workable value. I do lose out on a significant amount of vision at the edges, but, since this isn't a competitive FPS, it is worth trying it for the immersion tradeoff.

The Problem:

Fiddling with the .ini fixed all the UI problems, but the way FO3 handles FOV causes more persistent troubles.

When zooming in with the pistol I noticed that my FOV actually increased, effectively zooming out. This was true of several weapons. This is because each weapon in the game has a value known as Sight FOV. Unfortunately, this value is fixed, and is not dependent on the game's FOV. By reducing my FOV to 53.13, I had reduced it below the Sight FOV of most non-scoped weapons.

Another related, but separate, problem occurs with scoped weapons. When zooming with a scope, the "hole" in the texture mask is wider than the render window, causing bars to appear on either side.

The Solution:

I'm looking for input on how to go about fixing these problems. The latter problem should be relatively easy-- scaling down the texture file and filling in the black space should cover the bars.

The first problem, however, seems to be more, well, problematic. A workable Sight FOV value can be obtained by taking the ratio of the original Sight FOV and the Original FOV, and then multiplying by the new FOV. Unfortunately, this must be done for every weapon, and every weapon added by a mod. Are there any modding utilities that allow for scripted mass edits, or am I stuck going through and changing the value for every weapon I get? If there is, would it be practical to write a modifiable script for use by anyone who changes their FOV, either narrowing or widening?

My knowledge of FO3 modding is minimal, being based largely on half-remembered Morrowind modding, so please feel free point out any glaring errors in my plan.