= Small mods that change the visuals =

Can I use the work from these mods for my own project in the future?

Well, of course.

Regarding the splash screens (cutscenes), draw those frames as scrolls. Make them 1366 pixels or 1920 pixels long instead of 1024.

I didn't change the image width resolution; if I remember correctly, I made edits to DialogueScreen.(WindowScreen).xdb([<HorAlign>ALIGN_SCREEN</HorAlign>] etc.), DialoguePanel.(WindowSimple).xdb and DialoguePanel.(WindowSimpleShared).xdb.
It's not that easy to explain — better to compare the files from the mod with the originals yourself, experiment a bit, and then you'll understand how file editing works!