can I change materials/textures in the game files to reduce lag or just to make it look cooler?

ye i think so

@SniperDogeSR Yup! As long as they aren't heavily abused (Such as making non transparent walls transparent) But if you're downloading texture packs from a trusted source you should be fine : )

If it isn't giving any any advantage, It's fine but if it is no

Imagine you were aloud to use glass textures, easy to tell the rng