Best way to perform a texture animation sequence?

I have seen a few scripts to do texture animations,

what is the smoothest method?

is there a way to get a computer’s speed for libload,
and decide how early to start pre-loading something?

the texture animation is going to be for a opening sequence, so there will not be much else going on, but I do wish to use large animated textures in game as well,

These are separate topics. I will continue with the topic from title:

The question is what you are aiming for.

It seems you want to show a “cutscene”. I suggest to use the VideoTexture module and project a video on a plane. Unfortunately you need Python to do this.

Build-IN UV animation
If you want looping texture animation you can use the build-in UV animation (check the UV-Editor). But it does not allow much control over the animation.

Custom UV manipulation
You can animate the UV coordinates with a Python controller. This is usually known as UV-Scroll.

Custom Texture manipulation
You can manipulate the texture itself with the VideoTexture module. This gives you a lot of options but requires some skills with Python and the BGE API. This includes: render-to-texture, mirror, video and dynamic texture.