Noob Question: I need some Help with Texture Coordinates + Vertex Color to deform UV's

I was tinkering with UE Materials and seeing tutorials on Flow Maps and stuff.
My Question is…

What is the relation between texture coordinates and Vertex Color if I want to distort a texture?
I mean, I can paint like the green or red channel in vertex paint mode and add (or multiply or append the channels, dunno what’s 100% right, i’m kinda noob) those channels to the original undistorted texture coordinate, and then feed that into a texture UV and it does… something (it distorts, but a little too much and looks bad overall).
It feels (and I kinda know) like i’m doing something super wrong but i can’t put my finger on what’s it.
By the way, the vertex color (map?) that is “baked” (maybe?) and mixed with my original Texture Coordinates is tiled in any way? or it encompases the whole mesh by default?

Also, a relatively related question. Why if I plug my Texture Coordinates directly to the base color as a color vector I can only see 1 repetition across the entire mesh instead of the tiled result (that I can obtain normally when I plug the Texture Coordinates node into an UV input of a texture that goes into a tiled uv from a mesh?

My math and my english suck, so yeah… bear with me, any explanation on the topic would be greatly appreciated.

Also, this is not for a project or anything like that, just for pure curiosity, I don’t need so much a solution to the problem more like an explanation on this topic.