I've managed to center a few more things in a recent test build of Widescreen Fixer.

Trying to center things while actually playing (not at the main menu) is a bit more tricky. Every time you press the escape key it relocates everything in memory. Also when you alt-tab, it will bring up the menu, which relocates everything in memory. That makes it tricky just because I have to alt-tab out to search for values, and as soon as I alt-tab the addresses change making my previous search invalid. I'll get it eventually, though. The cutscenes are my biggest concern.

Edit:
I managed to find the FOV. Unfortunately this will be a very tricky one.

The FOV used by the game are stored in radians. The default seems to be 0.6981316805, or roughly 40 degrees. Zooming with the sniper rifle is about 10 degrees. The regular view and zoom view for all weapons is consistent. It does not change no matter what your aspect-ratio is. The cutscenes use the same address in memory, but are more tricky in that they use pre-set FOVs for various scenes within the cutscene. The values are affected by your aspect-ratio. This will need further investigating.

Edit 2:
I've managed to change a part of code that will scale either the horizontal or vertical FOV correctly. However, it's still reversed between cutscenes and gameplay. During gameplay, it will leave the vertical scale untouched and scale horizontally just fine. For cutscenes, it will scale vertically, leaving the horizontal view stretched out across three screens. I'm still working on it.