In general this means that you're missing an eye mod or something probably the http://www.tesnexus.com/downloads/file.php?id=17123.
I assume that you mean a dead npc after you have hit it, but unfortunate I can't help you much with that problem.
Anything related to clothing issues may be an unsolved mod conflict.
This "huge yellow squares" is only a reminder to you of a missing mesh in some mods (mostly recently installed).


If you not use any overhaul such as FCOM, MMM or the OOO mods you can remove all of the overhauls related Cobl files from the your loadorder and remember that you must merged the "Cobl Filter Late MERGE ONLY. esp into bashed patch, because if you don't that you will have a constant CTD if it's activated as unmerged.
The Cobl Silented Equip Misc.esp I'm not sure about, I can only suggest that you ask your question in the correct mod thread.

Ok I did a second look through of your Mods and I noticed something that caused problems for me and that is roberts male body. I had to disable that and remove it never did get it to work with out messing up the eyes and the khajiit skin blotching I would suggest also actually looking in NPC's eyes and seeing if instead of black they arent just missing (google eye), Look at the khajiit's male or female and cast a disrobe on them or just kill one and look if the body looks messed up almost like a patchwork quilt. If it looks like that then Roberts male body is the most likely cause.

I did as you said and removed roberts male body, who wants to see naked men anyway? And things changed, they're still messed up, but maybe in a way that its easier to figure out the problem:

Eyes:

First of all, brown, blue and green eyes are the only ones that appear correctly, I'm guessing because these are the vanilla human eyes. Argonian eyes appear black, same with Khaijit eyes.

Cobl races:

All of them are messed up in some way or another
Dark seducer: They have grey ears but a white skin tone meaning theres a skin problem somewhere
Ohmes raht: Now these guys have messed up colors, either a dark green or a murky blue AND NO EYES!
Xivilai: Has no head, basically a floating jaw
Hidden elf: Same as above
Golden Saint: Same as dark seducer, different skin tone than its golden ears.

Hair:
Vanilla hair works and some of the cobl ones, by some I mean 2 or 3 out of all of them

Maybe I have to overwrite some textures or folders, I believe Ozmo's high rez skin and textures caused this, but since it came with its own installer I cant figure where I have to look to delete them.

Alrite, I readded the Cobl resource pack overwriting everything in the texture folders and it fixed almost ALL of the problems! Only 2 things remain:

All the eyes work, except that the default eye color for khaijits, orcs, argonians and darkelfs are black (as in pitch black) is this how its supposed to be? In the character selection screen I can choose another color but since the default color is black my main concern is that all the NPCs i will encounter of these races will have that eye color, or is this how Cobl intended it to be?

And finally I couldnt get around the golden saint, dark seducer ear/skin tone thingamajig.

Are you BOSSing and Bashing.
Follow the recommended flags from BOSS.
If so What are you checking in the bashed patch for the Npc's. Checked areas should be Race Records, and Import NPC faces. that is all that I can see that have NPC sections.

Ok are you Omod installing these Mods using OBMM or just dumping them in the data folder. I if you are using OBMM I would deactivate HGEC and the COBL's (All of them). Then install HGEC Test the install, If it works fine then Install the COBL's. Test I think you have a texture problem still For the most part the dark seducers and others are from COBL. The reason I sugest going back and installing HGEC is that you are still having skin texture problems.
A way to make sure you have a good load, would be to take it back to square one (Remove Oblivion) and then reinstall, You have learned alot from this one. When I first started Adding Mods I had to do that about 4 times the first week.