Yeah i think we all know why we downloaded this.

You can't have 2 of the same files in 2 places.
It's best to move the files from this mod to the main game's override folder, unsub from this mod and then work on those files.
I have zero experience with how that works on a Mac, sorry.

I'm trying to edit the skin, but every time I do, the model reverts to the standard model and thus the skin gets jumbled up on the model. Is there a way around this which doesn't involve KOTOR tools? I'm on mac.

Yes, but it's a bit complicated and I'm not really up for doing it for this one.
You could overwrite an existing model or you could use the Revan robe model slot. I have a few mods that do the latter, they have (R) at the end of the title.

Is there a way to make this into it's own clothing set?

So I have this and when I load my save, the texture is completely gone.

fair enough there a shame aswell they all look so nice wouldnt mind having them but if something i have conflicts with them then no worries i do have a disc version of the game aswell so i could install it on that aswell lol

Nothing obvious comes to mind, sorry.

i would show you exactly what it does but i dont know how to upload printscreens

is there any possible mods that could be conflicting with it by any chance like maybe bastila's robes or the vaklu main char mod? i have a fair few clothing mods for armor in the game but nothing for the underwear apart from this

Don't ever use two mods that do the same.
But I don't think that's your problem and I'm afraid I don't know what's causing your issue.

i've had both the A and B versions of this mod but it keeps showing a silver chromy type of the normal underwear do you have any idea on why this happens i've tried have just 1 or the other of the mods and both at the same time i dont have any other underwear mods either installed so im not sure what could be doing this