You can change the resolution for the main window in which you can take pictures by editing the following line under [video]
battle_resolution = 1024 768 <<default
Also, you might have to change the actual graphics settings inside the editor. Mine are already set to medium high, but if your computer is faster, or slower than mine, you might have to change it even higher or lower.
Remember that, this is almost the same as your actual game.
Just look under [video] and you'll see which ones you can edit.
Example: Unit_Detail = highest (could be, high, medium, low).
Too much detail = lag.
Under the [replay] is where the .bat file find your replay. Remember to actually play a battle and save your replay.

Otherwise it doesn't work.
At the end of this line:
file = C:\Program Files\SEGA\Medieval II Total War\mods\Stainless_Steel_6\replays\
Replay.rpy
If you saved your replay under a different name, you must rename the highlighted word to whatever name you have given it, and make sure to put .rpy at the end of it.
I am guessing that [features] lets the editor find the mod.
Also, [capture_tga] does not work?