95% of my mods are re-textures. Is this really necessary?
Better safe than sorry. It literally takes 5 seconds. If 100% of your mods were retextures I'd say forget about it, but who knows with that 5%.
The only real issue here is those 8 deleted references. Basically, if a mod tries to call on those, your game crashes. What TES5Edit does is it undeletes them and just disables them so they're there if mods need them.
So, yes, you don't 100% have to do this, since your mods might not requires those references. But unless you know the inner workings of them, and everything they use, can't say for sure. I'm making this sound like it's a cure for cancer or something. It just helps prevent crashes is all. Crashes that may or may not be a threat with your mod loadout.