Texture strategies (how Unreal processes textures)

Hi everyone,
I have been using unreal for archviz for quite some time but it was usually small projects for pc and I never had to push it to the limits.
Recently I started working on bigger projects and also I started using oculus quest 2 so I started dealing with bottlenecks since the content became bigger and the hardware more limited.

I want to ask something to understand how ue deals with textures and what my strategy should be.
In the example above,We have a simple model which requires 5 materials or 1 material (atlas). the questions are the following:

If your purpose is performance,

  1. Is it better to use a large resolution texture/material or many small? (case 1 vs 3)

  2. If you repeat the same model many times do you have as many draws, or are the materials called once and used for each model? (e.g. in case n.2 we have 4 models with 5 materials, does this mean 4*5 = 20 draws or 5 * 1=5 draws?

  3. If you have the same actor repeated 4 times in your scene, is it lighter than having 4 different actors even if the have the same materials? (case 2 vs. case 5)

No answers…
is the question:

a) Not applicable
b) Difficult to answer
c) based on wrong assumptions
d) boring