In regards to the bad textures : It was due to Iray's memory limitation when it comes to rendering.
To make it simple, scene sizes had to be below a certain amount of Vram for Iray to consider using your graphic's card to render instead of the cpu (CPU is much, much, much slower). Unless you have a Titan RTX or the soon to be RTX 3090, most developers (me included) had to construct most of their scenes with this limitation in mind.
As an example, A single character can take close to 1 Gigabyte of V-ram and that's not even including the background or anything else you wanted to add on the scene. Most scenes are impossible for me to make unless I make severe cuts to all the assets that are involved.
So if I want to construct a big scene (Let's say the academy or scenes with 4-6 characters), I had to sacrifice something to make it work with Iray. Textures are the most resource intensive aspect of any rendering, so to cut down the memory usage, I had to reduce almost all of the sizes of the textures down to 1/2k and outright remove some of them completely. That's why you see these kinds of issues popping up. I've since found a much better way to circumvent around this, so this wouldn't be as big of an issue coming forward.
To summarize, the texture issues are something that I'm very aware of, and they will not be as apparent in the future. Unfortunately, unless I own a god-like rig, which I don't, this won't go away completely until I could get my hands on a better one. Just think of this as a limitation because of budget and inexperience.