everything is letterboxed! (even vids that shouldn't)

[IriDium]

You can cut a small section from a file using VLC convert/save. Just cancel it once you have about 2 minutes worth.

BTW: Both images posted are from Jack Reacher

However, I don't see the need anymore.

The original is 1912 x 792 which gives an aspect ration of 2.41:1 (1514304 Pixels)

A normal 1080 TV is 1920 x 1080 which is an aspect ration of 1.78:1 (2073600 Pixels)

So the movie will be displayed letterboxed.

See XBMC Aspect Ratio

Gotham has a setting in Video -> Playback "Allow error in aspect ratio"