hi,
basically you have 3 problems (says me if i'm wrong),
1-you can't have these hairs,
2-when you try to make her nude you have the hood items who staying on her
3-when you try to put the towel on her you don't have the good textures.
Well, first you must to know than the hairs are considered like a "helm" in the creation kit.(because it's a legit solution for have the HDT hairs on the NPC), maybe this information can enlighten you.
For the nude problem with the hood, if you remove all items in her inventory, sorry i have no idea how the hood can staying on her.
For the towel problem, i think the mod is badly installed.
I recommand to you to install firt the mod manually, (open the archive and put the data file in you skyrim folder, erase when asked, no need to remove the nexus version), for the other problems, you have maybe a mod or something who modify the base inventory in your game, because i have no idea how your probem can be possible with the vanilla version.
So, try in first to install the mod manually and says me if that have changed something.
I'm afraid manually installing the mod did not change anything. Just from removing one clothing and then removing the rest of the apparel she still has her suit with the hood on. Since you mentioned that there could be a mod causing issues I do have 100 mods (I'm kind of a mod junkie). One that comes to mind is a mod that changes the female vanilla clothes to be more revealing. I have SkyHair that although doesn't change anything vanilla it adds some hairs to the game. Finally I do have some custom races installed. I link some images from my nexus mod manager to show you what mods I have so you wont have to do much detective work. I greatly appreciate your help!
Here are the photos: Nexus Mod Manager Photos.docx
Have you the same problem with Ciri?
It's possible you have some conflicts with your race mods, because if i remember, a guy have been mentioned some glitchs with Ciri and a race mod.
(Race mod are always glitchy).
I haven't checked Ciri yet. I will go visit her and see if she has the same issue as Yennefer. If you checked the word document (I do not have snippet to make them JPEGs) I do have a couple custom races installed and I could try disabling them to see if it can resolve the issue. Many thanks!
UPDATE: I checked Ciri (before I disabled the custom race mods) and strangely she had her boots unequipped and her hair was fine. I took her clothing and she was not naked either and the only apparel that was not equipped was her boots. I gave back her clothes and the boots equipped onto her, from there I noticed that the equip arrow for showing what apparel was equipped on your character and NPC was marked only on Ciri's boots. The rest of the clothing was not equipped but still showed on Ciri. Even after I disabled the race mods I was still having the same issues with both Yennefer and Ciri. This is definitely confusing and weird and I have no clue as to what other mod could be causing the problem. I still appreciate that you are willing to solve this piece by piece and I will try playing some other characters (vanilla races) and see if its not just my one character im playing (Nord).
UPDATE 2: Even when playing different characters the problems still persist.
The problem is every body have a different Skyrim with the mods who modify the vanilla game, it's why sometime it's hard to find a solution.
But it's the rules of modding world, we must to do with it.
I think you have some scripts who modify the inventory of your NPC or something like that.
But, don't forget if you change some things with any controls you can ruin your game. It's why sometime it's preferable to "accept" some bugs (or to find a fresh solution) and have a game who staying "alive".